Hazrat Khadijah (radhiyallahu ‘anha) went to Waraqah bin Nawfal and explained to him the incidents that transpired during the journey of Rasulullah (sallallahu ‘alaihi wasallam), the statement of the monk and the manner in which the angels were shading him. Waraqah remarked, “O Khadijah! If these incidents are true, then most certainly Muhammed is the prophet of this ummah. I am well aware that a Nabi will come to this ummah whom we are awaiting and whose arrival is imminent.”

After hearing of these incidents, the desire entered the heart of Hazrat Khadijah (radhiyallahu ‘anha) to marry Rasulullah (sallallahu ‘alaihi wasallam). Hence, two months and twenty five days after his arrival from the Syrian trade journey, she sent a proposal to Rasulullah (sallallahu ‘alaihi wasallam). After consulting his uncle, Rasulullah (sallallahu ‘alaihi wasallam) accepted this proposal.

(Extracted from Seeratul Mustafa 1/111)