Reference: http://www.alfawzan.af.org.sa/node/16639
Question: What is the expiation for not fasting during Ramadhaan without a[n Islaamically acceptable] reason? [It’s just that] he did not fast for three days, so if you could explain how much exactly that would be.
Response: He must repent to Allaah (‘Azza wa Jall) for what he has done, because it is not permissible for him not to fast [during Ramadhaan] without a[n Islaamically acceptable] reason. He is also required to make-up the fasts for [all] the days [in Ramadhaan] which he did not fast, and he must hasten in doing that.
