Swore to Say a Certain Formula of Exalting the Mention of the Prophet
9-6-2020 | IslamWeb
Question:
Aoa, few years ago I took an oath on a condition and the condition got fulfilled. I said that I will recite "Jazzalahu ana muhammadan Sallallaho aliehe wassalam ma hua ahluhu" DAILY 200 times then I said 500 times. Now, I'm confused as this durood shareef isn't authentic or so. What should I do with it? Should I change it.? Or can I just stop this? And also tell me do I have to give kafara on daily basis? If so it's too hard for me I cannot do it. Can I stop this by any means?
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
To say: “Jaza Allaahu ‘anna Muhammadan ma huwa ahluhu (May Allah reward Muhammad, sallallaahu ‘alayhi wa sallam, for (guiding) us with befitting rewards),” is a good supplication, but it is not one of the reported wordings for invoking exalting the mention of the Prophet, sallallaahu ‘alayhi wa sallam. If a person makes an oath to recite this supplication, it counts as a binding oath, and either he has to fulfill it, or else it would be a broken oath and he would be obliged to offer Kaffaarah (expiation) for breaking it. If the wording of the oath was, for example, “By Allah, if such-and-such happens, I will say ‘Jazza Allaahu ‘ana Muhammadan, sallallaahu ‘alayhi wa sallam, ma huwa ahluhu’ 200 times; rather 500 times,” the oath would be dissolved by offering one expiation for breaking it. The repeated breaking of it does not necessitate giving multiple expiations, meaning that you are required to offer the expiation only once. Az-Zarkashi 
said in Al-Manthoor: “Whenever a person breaks the oath, it is dissolved, and he does not have to offer an expiation every time he breaks it (i.e. the oath of that incident).” [End of quote]
The expiation for breaking an oath was previously explained in Fatwa 102811.
For more benefit on whether repeated breaking of vow or oath requires repeated expiation, please refer to Fataawa 367117, 356647, 311782, and 252454.
Allah Knows best.