Is it necessary for someone who masturbated during Ramadan, being unaware that it invalidates the fast, to make up the days (qada') or offer expiation (kaffarah), given their ignorance of the number of days?

Scholars have differed regarding one who commits an act that invalidates the fast, being ignorant that it invalidates it. The preponderant opinion is that their fast is not invalidated, and they are not required to make up for it. This is because the injunction is not established until after notification, as Allah the Almighty said: "that I may warn you thereby and whoever it reaches." Accordingly, there is no making up or expiation for one who practiced masturbation while ignorant that it invalidates the fast, provided that semen was discharged. However, if semen was not discharged, then their fast is valid.