While Rasulullah (sallallahu ‘alaihi wasallam) was performing salaah with Hazrat Khadeejah (radhiyallahu ‘anha), Hazrat Ali (radhiyallahu ‘anhu) stood observing them engaged in salaah. After Rasulullah (sallallahu ‘alaihi wasallam) completed the salaah, Hazrat ‘Ali (radhiyallahu ‘anhu) asked, “What is this that you are engaged in?” Rasulullah (sallallahu ‘alaihi wasallam) replied, “This is the deen of Allah Ta‘ala which He has chosen for His servants and which He sent to the world with his Prophets (‘alaihimus salaam). I am inviting you to Allah Ta‘ala; to worship Him alone and renounce the idols of Laat and ‘Uzza.”

Hazrat ‘Ali (radhiyallahu ‘anhu) replied, “This is something which I have never heard of before today. I do not wish to take a decision without discussing this with my father, Abu Taalib.” Rasulullah (sallallahu ‘alaihi wasallam) did not want Hazrat ‘Ali (radhiyallahu ‘anhu) to reveal his Islam before Rasulullah (sallallahu ‘alaihi wasallam) announced it publicly. Hence, he said to him, “O ‘Ali! If you do not wish to embrace Islam, then refrain from mentioning it to anyone else.”

Not even a night had passed when Allah Ta‘ala guided the heart of Hazrat ‘Ali (radhiyallahu ‘anhu) towards Islam. The following morning, he presented himself before Rasulullah (sallallahu ‘alaihi wasallam) and asked, “What are you inviting me towards?” Rasulullah (sallallahu ‘alaihi wasallam) replied, “I invite you to bear testimony that there is none worthy of worship besides Allah Ta‘ala alone, who has no partner, and I invite you to renounce Laat and ‘Uzza and disassociate yourself from idols and idol-worship.” Hazrat ‘Ali (radhiyallahu ‘anhu) then embraced Islam. (Usdul Ghaabah 3/283, Seerah Halabiyyah 1/383)