What is the ruling for a person who eats or drinks absentmindedly while observing a voluntary fast?

Islam is a religion of ease and facilitation. Allah Almighty says, “And He has not placed upon you in the religion any hardship” (Quran, 22: 78). In accordance with this principle, Islam has legislated valid excuses that permit a fasting person to refrain from fasting in Ramadan, “So whoever among you is ill or on a journey—then an equal number of other days [are to be made up]” (Quran, 2:184).

Furthermore, Islam has permitted a fasting person who eats or drinks out of forgetfulness to continue the fast, based on the hadith of the Prophet (peace and blessings be upon him), when he told a person who ate and drank absentmindedly while fasting, “It is Allah who fed you and gave you to drink” (recorded by Abu Dawud).

If this ruling applies to the obligatory fast, then it applies with even greater reason to the voluntary fast, based on the hadith, “Indeed, Allah has pardoned my Ummah for mistakes, forgetfulness, and what they are compelled to do” (reported by Ibn Majah).

Based on this, the fast of one who is fasting—whether in Ramadan or otherwise—and eats or drinks out of forgetfulness, remains valid.

And Allah Almighty knows best.