Qur'an 58:4

فَمَن لَّمْ يَجِدْ فَصِيَامُ شَهْرَيْنِ مُتَتَابِعَيْنِ مِن قَبْلِ أَن يَتَمَآسَّا ۖ فَمَن لَّمْ يَسْتَطِعْ فَإِطْعَامُ سِتِّينَ مِسْكِينًا ۚ ذَٰلِكَ لِتُؤْمِنُوا۟ بِٱللَّهِ وَرَسُولِهِۦ ۚ وَتِلْكَ حُدُودُ ٱللَّهِ ۗ وَلِلْكَـٰفِرِينَ عَذَابٌ أَلِيمٌ

And he who findeth not (the wherewithal), let him fast for two successive months before they touch one another; and for him who is unable to do so (the penance is) the feeding of sixty needy ones. This, that ye may put trust in Allah and His Messenger. Such are the limits (imposed by Allah); and for disbelievers is a painful doom.