What is the ruling on the fast of one who committed the sin of masturbation during the day in Ramadan out of ignorance, and is expiation by feeding or fasting required of him?

If you masturbated during the daytime in Ramadan while you were an adult and were unaware that it invalidates the fast, you are only required to make up one day [of fasting], and no expiation (kaffarah) is due upon you, because expiation is only required for sexual intercourse. However, if you were not an adult at that time, then nothing is due upon you. You must repent to Allah for this forbidden act.