Is it obligatory to re-pay Zakat al-Fitr if the father gave it on behalf of his son without his knowledge or authorization, given that the son believes in the correctness of Abu Hanifa's view that it is not valid, and is the son excused for delaying it?

The Hanafi School's view on Sadaqat al-Fitr:

- It is obligatory for a minor child.

- It is not obligatory for an adult of sound mind or for the wife.

- It is permissible for the father to give it on behalf of his adult son and wife, as a matter of preference (istihsan), if they are his dependents; this is due to the customary existence of permission, and this is what the fatwa is based upon.