Not even a night had passed when the desire to accept Islam entered the heart of Hazrat ‘Ali (radhiyallahu ‘anhu). The next morning, he presented himself before Rasulullah (sallallahu ‘alaihi wasallam) saying, “What are you inviting towards?” Rasulullah (sallallahu ‘alaihi wasallam) replied, “Bear testimony that Allah Ta‘ala is the only deity worthy of worship. Renounce Laat and ‘Uzza and express your aversion and disassociation from idolatry.”

Hazrat ‘Ali (radhiyallahu ‘anhu) then embraced Islam. For quite some time thereafter (some narrations mention that it was for one year), he concealed his Islam from his father, Abu Taalib.

After Hazrat ‘Ali (radhiyallahu ‘anhu), the freed slave of Rasulullah (sallallahu ‘alaihi wasallam), Hazrat Zaid bin Haarithah (radhiyallahu ‘anhu), embraced Islam and performed salaah with him.

(Extracted from Seeratul Mustafa 1/155-156)