Question to Shaikh Al-Allāmah Muqbil Ibn Hādi (rahimahullāh):
If a person is taking his pre-dawn meal (Sahoor), and the Mu’adhin calls the Adhān (for the Fajr Prayer) — is it obligatory on the person to spit out what is in his mouth or should he eat and swallow it?
“As for what is in his mouth, he should not spit it out however, he must not eat anything after that, unless he has some water (or a drink that is in his hand). This is due to what is reported in the “Sunan of Abu Dawood” from Abu Hurayrah (radiyallahu ‘anhu) that Allah’s Messenger (ﷺ) said, “If the Mu’adhin calls the Adhān and there is a vessel in the hand of one of you, then let him take from it what he needs.” So there is no harm if he drinks when the Mu’adhin calls the Adhān (for Fajr prayer) with the condition that the water was (already) in his hand.”
(Fadā’ih wa Nasā’ih, page 76)