The husband is obliged to spend on his wife’s maintenance, on a reasonable basis, because Allah, may He be exalted, says (interpretation of the meaning):
“Men are the protectors and maintainers of women, because Allah has made one of them to excel the other, and because they spend (to support them) from their means”
[an-Nisa; 4:34]
“Let the rich man spend according to his means, and the man whose resources are restricted, let him spend according to what Allah has given him. Allah puts no burden on any person beyond what He has given him”
[at-Talaq 65:7].
It was narrated that Mu‘awiyah al-Qushayri (may Allah be pleased with him) said: I said: O Messenger of Allah, what are the rights of the wife of one of us over him? He said: “That you feed her as you feed yourself, clothe her as you clothe yourself, do not strike the face, do not disgrace her and if you want to shun her (by way of disciplining her) do not leave home.”
Narrated by Abu Dawood (2142) and Ibn Majah (1850); classed as saheeh by al-Albani in Saheeh Abi Dawood.
This has been discussed previously in fatwa no. 145722
If the husband fails to spend on his wife’s maintenance, then she has the choice of leaving him or putting up with him.
If she chooses to put up with him, in the hope that he will change, if he is withholding her maintenance out of miserliness and stinginess, or until his financial situation improves, if he is not well off, then she is not obliged to allow him to be intimate with her Ash-Shirazi ash-Shaafi‘i said in al-Muhadhdhab fi Fiqh al-Imam ash-Shaafi‘i (3/155):
If she chooses to stay after he becomes unable to spend on her, she is not obliged to allow him to be intimate with her, and she may leave his house, because allowing intimacy is in return for maintenance, so it is not obligatory when there is no maintenance. End quote.
Muhammad Najeeb al-Mutee‘i said in his Sharh (20/169):
