Making a vow to perform tahajjud
Q: The way before I made a prayer that if I succeed in so and so I will try my level best to offer tahajjud regularly. So if for some reason I skip a day or days then did I commit a sin? Offering tahajjud regularly for the sake of mannat, does this make the reward of tahajjud any less? I made supplication like this "Allah apne kamyaabi di to mein tahajjud ki pabandi karney ki puri koshish karungi "