The wisdom behind the sixty-day expiation for intentional fast breaking in Ramadan
Why has Allah prescribed the compensatory expiation for intentional fast breaking in Ramadan to be sixty days in a row?
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.
First of all, the sixty-day expiation for breaking the fast during a day in Ramadan is due only if the fast was broken by sexual intercourse, according to the majority of scholars. Furthermore, expiating by giving meals to sixty indigent and poor people is invalid, according to the majority of scholars, unless the violator is unable to observe the sixty-day fast.
As for why Sharee‘ah ordains this, then Allah The Almighty does not ordain anything except for a great wisdom and predominant benefit, which we might or might not know, or know only in part. In all cases, we should surrender and fully submit to Allah The Almighty and comply with His command. It is permissible for a Muslim to ask about the wisdom behind a certain ordinance, provided that his compliance and submission does not become contingent on this understanding.
As regards the wisdom behind the mentioned ordinance, it might include deterrence for one whose faith is so weak that he might want to violate the sanctity of the fast, and to discipline the one who violated that sanctity in order not to do the same again. This wisdom might also include removing the sin into which the fasting person fell.
Allah Knows best.