Answered by Ustadh Tabraze Azam
Question: Assalam alaykum
Should I fast if I fail to fulfill a promise to Allah?
Answer: Wa alaikum assalam wa rahmatullah,
No, you do not need to fast if the action stated in your promise isn’t fulfilled.
Promises to Allah Most High are merely promises, and thus, aren’t subject to the rulings pertaining to oaths and the like.
But, generally, you should avoid making a promise unless you (1) have the firm commitment to fulfil it, and (2) are actually reasonably able to.
This is on condition that you used the phrase “I promise,” contrary to “by Allah,” or a similar utterance, which is the phrase used to make oaths binding.
Ask Allah Most High for forgiveness, and facilitation in the matter you are striving to accomplish.
[Nahlawi, al-Durar al-Mubaha fi al-Hazr wa al-Ibaha (125)]
And Allah Most High alone knows best.
[Ustadh] Tabraze Azam
Checked and Approved by Shaykh Faraz Rabbani
Ustadh Tabraze Azam holds a BSc in Computer Science from the University of Leicester, where he also served as the President of the Islamic Society. He memorised the entire Qur’an in his hometown of Ipswich at the tender age of sixteen, and has since studied the Islamic Sciences in traditional settings in the UK, Jordan and Turkey. He is currently pursuing advanced studies in Jordan, where he is presently based with his family.