I vowed to fast until my need is fulfilled. Does this constitute transgression against Allaah Almighty? My sister told me that this is impermissible and constitutes a challenge against Allaah Almighty because it is as if I am saying: "O Allaah, if You do not give me such-and-such, I will continue to fast." My need is that Allaah Almighty grants my sister a suitable husband. Every time a suitor proposes to her, nothing positive happens. So I vowed to continue to fast until she gets married. My sister is the one who forbade me from doing this. What is your opinion?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

In brief, we would like to thank the questioner for her extreme care for her sister. We ask Allaah Almighty with His Most Beautiful Names and His Sublime Attributes to achieve our hope and hers. By reviewing the two mentioned Fataawa, the questioner will know that she should not have made such a vow in order not to fail in fulfilling a matter that she imposed upon herself while she did not have to do it. It was enough for her to resort to Allaah Almighty with supplication at the times when supplications are most likely answered, such as during prostration, before dawn, upon hearing the Athaan (i.e. call for prayer), between the Athaan and the Iqaamah (i.e. call to establish prayer) and at other times when supplications are most probably accepted. However, as this has already happened, the questioner should fulfill her vow and fast until Allaah Almighty fulfills her need because her vow is a vow of obedience. Whoever vows to obey Allaah Almighty should obey Him according to the Hadeeth. If she is unable to fulfill it, then she should offer an expiation like that of breaking an oath. We would like to highlight the fact that it is impermissible to fast on days of the days of 'Eed and during menses and postpartum bleeding because fasting is prohibited at those times.

Allaah Knows best.