Why Do We Stop Eating 10 Minutes before We Begin the Fast?

بِسۡمِ ٱللهِ ٱلرَّحۡمَـٰنِ ٱلرَّحِيمِ

The following is with regards imsak, the act of abstaining from eating approximately ten minutes before the commencement of the fast. 

Most books of fiqh state that the wajib time to begin fasting is at true dawn, the time when the second adzan in pronounced.  Many fasting calendars, particularly of the Hanafi and the Shafi’i, recommend that people stop eating ten minutes before the true dawn.  It is recommended to delay sahur, the pre-dawn meal, to the last part of the night, before fajr, but to stop before about ten minutes, the extent of reciting 50 verses of the Qur’an, because of the hadits narrated by Sayyidina Zayd ibn Tsabit (r.a.). 

It is recorded in the Shaykhayn, from Sayyidina Zayd ibn Tsabit (r.a.), “We had sahur with the Messenger of Allah (s.a.w.), and then we got up to pray.” 

Sayyidina Anas ibn Malik (r.a.) asked, “How much time was there between the two?”  He was referring to the interval between imsak and fajr asw-swadiq. 

Sayyidina Zayd (r.a.) replied, “50 verses.” 

There are other ahadits about this, but they do not indicate any obligation.  Rather, this is a recommendation, by agreement, with the reasoning being not to enter a time in which there is doubt whether fajr has come in or not.  This has been explained in Imam Abu Zakariya Yahya ibn Sharaf an-Nawawi’s (r.a.) Majmu’, Imam Muwaffaq ad-Din Abu Muhammad ‘Abdullah ibn Ahmad ibn Qudamah al-Maqdisi’s (r.a.) Mughni, Imam al-Kamal ibn al-Humam’s (r.a.) Fath al-Qadir, Imam Muhammad Amin ibn ‘Abidin ash-Shami’s (r.a.) Radd al-Muhtar; and Imam Abu as-Sa’dat Manswur ibn Yunus al-Buhuti’s (r.a.) Kashf al-Qina’, amongst others.