Fasting is the last option in the expiation of an oath
29-5-2014 | IslamWeb
Question:
Salamwalaikum. I made many repeated oaths that I would no longer feel guilty about a particular waswas, so I set out conditions such as "to not dwell/obsess for more than 10 seconds at a time", "to pursue clarity of mind until clarity is achieved". I took around 144 oaths, and within the the conditions of the oath I said that IF i break the oath, I would only like to repay its expiation by offering 144x3= 432 days of fasting. My question is, if I have broken the oath, do I have to fulfill the terms that I must offer expiation by offering 432 days of fasting, or may I also consider offering expiation by feeding 10 person, 144 times over. I understand the severity of what I have done, my mind has felt imprisoned by this same waswas for around 13 months, and it has pushed me into deep despair and I have regretted what I have done, and in shaa Allah I will never act so foolishly in this matter. JazakhAllah Alf Khair
Answer:
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 
is His slave and Messenger.
We ask Allaah to cure you from this Waswaas (obsessive whispers). As regards these oaths, if they were a result of Waswaas, then they are not effective, but the oaths that you made willingly without being overcome by Waswaas, then they are effective.
In case the oaths are effective, then if you break them, you are only required to expiate once as the matter regarding which you had made the oath is of one kind – as it appears.
As to you setting the condition of fasting as an expiation, then there is no consideration for this. The expiation required for breaking an oath must be done in sequence, and fasting is not a sufficient expiation unless you are unable to feed ten poor people or clothe them or set a slave free.
For more benefit, please refer to Fataawa 87181 and 102811.
Allaah Knows best.