Ubayy ibn Ka'b

Ubayy ibn Kaʿb al-Anṣārī was from the Khazraj tribe of Madinah and one of the most preeminent Companions in the recitation and preservation of the Qurʾān. The Prophet ﷺ instructed the Muslims to learn the Qurʾān from four people, and Ubayy ibn Kaʿb was the first of the four named. He was present at the First and Second Pledges of ʿAqabah and was one of the earliest scribes of the Qurʾān in Madinah.

When al-ʿAbbās's secret letter reached the Prophet ﷺ at Qubāʾ, warning of the approaching Qurayshi army before Uḥud, Ubayy ibn Kaʿb was present. Since the Prophet ﷺ could not read (an-Nabī al-Ummī), he instructed Ubayy to read the letter aloud. The Prophet ﷺ then asked Ubayy to keep the contents confidential until further notice. This brief incident places Ubayy at the very first link in the intelligence chain that prepared the Muslims for Uḥud.

Ubayy ibn Kaʿb was also known for his deep ʿibādah (worship). The Prophet ﷺ said of him: 'The master of the Muslims is Ubayy ibn Kaʿb.' He lived until at least the reign of ʿUthmān (raḍiyallāhu ʿanhu) and was one of the primary authorities in the compilation of the Qurʾān.