One day in Ramadan, I happened to drink water just after the muezzin started the azan of the Fajr prayer by saying, “Allahu Akbar.” I was told by my uncle when I was young that doing this is permissible. Am I required to make up for that day? Am I also required to pay expiation for that same day?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Allaah Almighty says (what means): {And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night].} [Quran 2: 187] The verse indicates that the fasting person is allowed to eat and drink until the true time of dawn. What is meant here with the time of dawn is that through which the start of the day can be recognized and the prayer becomes due. Once dawn breaks, the Muslim must abstain from eating, drinking, and whatever may break his fast.

With this in mind, if in your region the azan for the Fajr prayer is usually called after the true prayer time has already started, then you must abstain from whatever breaks the fast as soon as the caller says “Allaahu Akbar.” If you eat after this, then your fasting is invalid and you have to make up for this day later on. However, if in your region the azan for the Fajr prayer is usually called before the true time for the Fajr starts, then there is no problem to eat while the muezzin is calling it. This is because what matters is the start of the true time of the prayer rather than the azan for the prayer.   

To conclude, if you were aware that the prayer time had already started while you were eating, then you are required to make up for that day, even if you were ignorant about the ruling. This is because such a ruling is well known in Muslim countries. Furthermore, whenever a Muslim is ignorant about a matter related to his religion, then he is required to ask the people of knowledge about it before he applying it. Allaah Almighty, concerning this, says (what means): {… so ask the people of the message if you do not know.} [Quran:21:7]

Allaah Knows best.