Poverty in Indonesia continues to increase from 2020 to 2021 and has increased by 4.17% (Statistik, 2022). The Indonesian government has implemented many programs to reduce poverty, but poverty continues to grow. One of the instruments in Islam to overcome poverty is the waqf instrument. Waqf is different from zakat instruments in terms of collection and distribution. Waqf can be collected from all humanity, not only Muslims and the benefits of waqf for all humanity are not seen from religion or ethnicity. The rewards from waqf also continue to flow to the wakif until the afterlife. So, waqf has a wider social impact than zakat. (Masrizal et al., 2023) (Sapir et al., 2023) (Zawawi et al., 2023) .

Muhammadiyah is a community organization that is more than a century old. Table 1 shows the waqf land owned by Muhammadiyah until 2023, which reached 21 million square meters. However, only 50% has been utilized, while 50% of the total waqf land has not been used (Hamdani, 2020). One form of land waqf utilization program is productive waqf through cash. Persyarikatan Muhammadiyah has been designated by the Indonesian Waqf Board (BWI) as nazhir of cash waqf since October 8, 2020. The potential for cash waqf from Muhammadiyah members could reach IDR 2.4 trillion annually (Furqon, 2020-11-05).

The conditions above are the basis for this research, namely knowing the behaviour of Muhammadiyah citizens’ becoming wakifs, especially wakifs in cash waqf instruments. This is to identify factors that can increase the realization of cash waqf collection. One of the behavioural models used in research on consumer behaviour or interests is the Theory of Planned Behavior (TPB). The TPB model was first developed by Ajzen (Bosnjak et al., 2020), that the factors that can influence a person's behavior in purchasing decisions are Attitude factors, Subjective Norms, and Perceived Behavior Control (PBC). Several previous research results show that these factors can influence consumer behaviour significantly, such as research conducted by Huda et al., Saifudin & Puspita, and Masrizal et al. ((Huda et al., 2018); (Masrizal et al., 2023); (Saifudin & Puspita, 2020)). However, as the TPB model developed, modified TPB emerged, where researchers added factors other than attitudes, subjective norms and Perceived Behavioural Control (PBC) in influencing consumer interest or behaviour. These additional factors are knowledge and Islamic religiosity factors. Research by (Huda et al., 2018), (Larasati et al., 2018), and (Masrizal et al., 2023) proves that knowledge and Islamic religiosity factors can influence a person's interests. However, the research of (Zawawi et al., 2023) has different results from other studies in that the knowledge factor does not significantly influence. Significant to a person's interests.

Based on the background description above, it is necessary to research the behaviour of Muhammadiyah citizens’, especially the interest of Muhammadiyah citizens’ becoming waqf. The factors used are knowledge, attitude, subjective norms, Perceived Behaviour Control (PBC), and Islamic religiosity to influence Muhammadiyah citizens' interest in becoming waqif.

The data analysis method used in this research is quantitative with a Structural Equation Model (SEM) approach. This approach was chosen because of the direct and indirect relationships between the variables in this research. The SEM method does not require a lot of data (Ghozali, 2014). The software used is SmartPLS 3.0

This research population comprises Muhammadiyah citizens’ including Muhammadiyah management leaders, Muhammadiyah members with membership numbers, and Muhammadiyah sympathizers. Because the population size cannot be known, the determination of the research sample is based on (Hair et al., 2013) theory that the number of samples is based on the number of research indicators multiplied by 5 or 10. The number of indicators for this research is 30, so the samples are between 150 to 300. 188 respondents filled out the research questionnaire.

The questionnaire used in this research was adopted from research by (Amin, 2022), (Baber, 2020), and (Rizal & Amin, 2017). The questionnaire to measure Waqf Literacy uses sources from the Indonesian Waqf Board. Table 2 below shows the statements in the research questionnaire to measure each research variable.

Waqf literacy in this study has a significant direct influence on Attitude (H1). The results of this hypothesis test support the study by (Masrizal et al., 2023), which found that the Waqf Literacy variable has a significant effect on the formation of respondents' Attitudes. So the higher the Waqf Literacy of Muhammadiyah residents regarding cash waqf, the higher the attitude or Attitude of Muhammadiyah residents regarding cash waqf and becoming a waqif. The hypothesis in this study is that the Waqf Literacy variable does not have a significant influence on the intention of Muhammadiyah residents to become waqif (H2). The results of this study differ from the results of the study by (Masrizal et al., 2023), which found that the Waqf Literacy variable significantly influences intention.

Islamic Religiosity in this study has a significant direct influence on Waqf Literacy (H3). This result is linear with the results of the study by (Masrizal et al., 2023) but different from the study by Dawami (2020) that Islamic Religiosity does not significantly influence consumer preferences. Research on the influence of Islamic Religiosity on knowledge is still minimal. Thus, the differences and similarities between the results of this study and previous studies are an opportunity to develop the relationship between the variables of Islamic religiosity and knowledge. The results of testing the fourth hypothesis (H4) that there is a significant influence between the Islamic Religiosity variable on Attitude show linear results with the studies of Jatmiko et al. (2024), (Masrizal et al., 2023), and Maulina et al. (2023). The results of this study differ from the research of Usman et al. (2022) that Islamic Religiosity has a significant indirect effect on Attitude. A comparison of the results of this study with previous studies shows that Islamic Religiosity has a direct and indirect relationship to Attitude. Islamic Religiosity also has a significant direct effect on intention (H5). The results of this study are linear with the research of Maulina et al.(2023), (Rizal & Amin, 2017), Amalia et al. (2019), and Jayanto & Munawaroh (2019). Research by Maulina et al. (2023) on the influence of Islamic Religiosity on cash waqf intention. Research by (Rizal & Amin, 2017) on the influence of Islamic Religiosity on cash waqf intention. Research by Amalia et al. (2019) on the influence of Islamic Religiosity on halal tourism intention. Research by Jayanto & Munawaroh (2019) on the influence of Islamic Religiosity on zakat paying intention. These results indicate that Islamic Religiosity can influence intention other than waqf, namely halal and zakat. Subjective Norms have a significant direct influence on attitude (H6). The results of this study are linear with the results of (Masrizal et al., 2023). There is still very little research that connects subjective norms to attitude. So it can be concluded that the Subjective Norm variable has a direct influence on the attitude variable based on the results of this study and the research of (Masrizal et al., 2023). However, Subjective Norm does not have a significant direct influence on intention (H7). These results differ from the results of research by (Baber, 2020), Maulina et al. (2023), Usman et al. (2022), Jatmiko et al. (2024), Muharromah et al. (2023), and the results of research by Asyari et al. (2024). The results of this study are in line with the results of the study by (Mujahidah & Rusydiana, 2023) that Subjective Norm does not significantly directly affect cash waqf intention.

The results of this study indicate that the PBC variable does not have a significant direct effect on attitude (H8). The results of this study are different from the results of the study by Xiang et al. (2023) that PBC has a significant direct effect on attitude. PBC in this study has a significant direct effect on intention (H9). The results of this study are in line with the results of the studies by Xiang et al. (2023), (Haron et al., 2023), Muhammad et al. (2023), Asyari et al. (2024), and Jatmiko et al. (2024). However, the results of this study are different from the study by (Mujahidah & Rusydiana, 2023) that PBC does not significantly directly affect the Cash Waqf Intention variable.

The attitude variable in this study has an insignificant direct effect on the intention variable (H10). The results of this study are different from the results of the study by (Masrizal et al., 2023), Dawami (2020), Xiang et al. (2023), Usman et al. (2022), Muharromah et al. (2023), and (Mujahidah & Rusydiana, 2023) that attitude can directly influence cash waqf intention. The difference in these results indicates that there needs to be research directly on the relationship between these two variables. Thus, the concept of a direct significant influence of the Attitude variable on intention becomes a strong concept.

This study’s results indicate a significant indirect relationship between the variables of Islamic Religiosity and Attitude through Waqf Literacy (H11). The research of (Masrizal et al., 2023) is linear with this study. The significance of the indirect relationship of Islamic religiosity to attitude is also seen in the research results of Usman et al. (2022). However, Islamic Religiosity in this study has an insignificant indirect effect on Intention through attitude (H12). The results of this study are different from the research of (Masrizal et al., 2023) that there is a significant indirect effect between Islamic Religiosity and Intention through Waqf Literacy. Waqf Literacy has an insignificant indirect effect on Intention through attitude (H13). The results of this study are different from the research of (Masrizal et al., 2023).

Islamic religiosity in this study has an indirect, insignificant effect on intention through Waqf Literacy and attitude (H14). The results of this study are different from the results of (Masrizal et al., 2023) because the results of (Masrizal et al., 2023) showed that attitude has a significant effect on intention. Meanwhile, the results of this study showed that attitude has an insignificant effect on intention. PBC and Subjective Norm have an indirect, insignificant effect on intention through attitude (H15, H16). These results are different from the research of (Masrizal et al., 2023). Islamic Religiosity also has an indirect, insignificant effect on Intention through Waqf Literacy (H17). These results differ from the results of (Masrizal et al., 2023) study that Islamic Religiosity has a significant indirect effect on Intention through Waqf Literacy.

The results of this study indicate that only the indirect effect of the Islamic Religiosity variable on Attitude through Waqf Literacy is significant. The results of this study support the results of (Masrizal et al., 2023). This significant indirect effect shows that the Attitude of Muhammadiyah members will increase with the increase in Waqf Literacy based on Islamic Religiosity.

This research contributes to the interest of Muhammadiyah citizens in becoming wakif from cash waqf. Variables that can directly influence Muhammadiyah citizens' interest in becoming wakif are Islamic Religiosity and Perceived Behavior Control (PBC). Meanwhile, other variables, namely Waqf Literacy, Subjective Norm and Attitude, do not directly influence the interest in becoming a wakif among Muhammadiyah citizens. The Islamic Religiosity variable, Waqf Literacy variable, and Subjective Norm significantly influence Attitude. Meanwhile, the PBC variable has no direct effect on Attitude. The Islamic Religiosity variable also directly influences the Waqf Literacy variable. The only significant indirect influence is the influence of the Islamic Religiosity variable on Attitude through Waqf Literacy.

Meanwhile, the indirect Islamic Religiosity variable on Intention through Attitude is not significantly influenced. The Islamic Religiosity variable on Intention through Waqf Literacy and Attitude is not significantly influenced. The Waqf Literacy variable on Intention through Attitude is not significantly influenced. The Subjective Norm variable on Intention through Attitude is not significantly influenced. The PBC variable on Intention through Attitude is not significantly influenced. The Islamic Religiosity variable on Intention through Waqf Literacy is not influenced considerably either. So, it can be concluded that of the 17 hypotheses, only 7 are significant or accepted, and the remaining 10 are not significant or rejected.

The implications of the results of this research for Muhammadiyah leaders and Muhammadiyah nazhir managers can pay attention to increasing Islamic Religiosity, Waqf Literacy, Subjective Norms, PBC, and the Attitude of Muhammadiyah citizens regarding cash waqf. So, the amount of cash waqf collected by the Muhammadiyah organization will continue to increase. The implications for future research include adding or replacing variables that influence people's interest in becoming wakif. This result is based on the interest determination coefficient value of only 47.8 %. The variables that need to be considered for future research are Trust, Transparency and other variables that can increase people's interest in becoming wakif.