Is the fasting person obligated to abide by the imsakiyya (pre-dawn abstinence) time or by the adhan (call to prayer)? Is the imsakiyya time from the Sunnah? What is its meaning, and why was it established? Is it the time of true dawn?

Servants are only obligated to do what Allah and His Messenger have made obligatory. Fasting a part of the night is not obligatory, and whoever makes it obligatory has spoken about Allah without knowledge. What is prescribed is to abstain from things that break the fast when the true dawn appears. As for what is known today as "Imsakiyah" (the time of refraining from food and drink before the true dawn), it is not prescribed. It is not part of the Sunnah to abstain from things that break the fast before the true dawn as a precaution. Rather, a person may eat and drink until the time of the true dawn begins, as the Prophet (peace be upon him) said: "Indeed, Bilal announces the Adhan at night, so eat and drink until Ibn Umm Maktum announces the Adhan."