Chapter: "And (remember) when the angels said: 'O Maryam (Mary)! Verily, Allah has chosen you..."
Narrated `Ali:
I heard the Prophet (ﷺ) saying, "Mary, the daughter of `Imran, was the best among the women (of the world of her time) and Khadija is the best amongst the women. (of this nation). - Sahih:Al Bukhari:3432 (islam)
Chapter: The marriage of the Prophet (saws) with Khadija رضي الله عنها and her superiority
Narrated `Aisha:
I did not feel jealous of any of the wives of the Prophet (ﷺ) as much as I did of Khadija though I did not see her, but the Prophet (ﷺ) used to mention her very often, and when ever he slaughtered a sheep, he would cut its parts and send them to the women friends of Khadija. When I sometimes said to him, "(You treat Khadija in such a way) as if there is no woman on earth except Khadija," he would say, "Khadija was such-and-such, and from her I had children." - Sahih:Al Bukhari:3818 (islam)
Chapter: The Virtues Of Khadijah, The Mother Of The Believers (RA)
'A'isha reported:
Never did I feel jealous of the wives of Allah's Apostle (ﷺ) but in case of Khadija, although I did no, (have the privilege to) see her. She further added that whenever Allah's Messenger (ﷺ) slaughtered a sheep, he said: Send it to the companions of Khadija I annoyed him one day and said: (It is) Khadija only who always prevails upon your mind. Thereupon Allah's Messenger (ﷺ) said: Her love had been nurtured in my heart by Allah Himself. - Sahih:Muslim:2435b (islam)
Chapter: The marriage of the Prophet (saws) with Khadija رضي الله عنها and her superiority
Narrated Isma`il:
I asked `Abdullah bin Abi `Aufa, "Did the Prophet (ﷺ) give glad tidings to Khadija?" He said, "Yes, of a palace of Qasab (in Paradise) where there will be neither any noise nor any fatigue." - Sahih:Al Bukhari:3819 (islam)
Chapter: The marriage of the Prophet (saws) with Khadija رضي الله عنها and her superiority
Narrated 'Aisha:
Once Hala bint Khuwailid, Khadija's sister, asked the permission of the Prophet (ﷺ) to enter. On that, the Prophet (ﷺ) remembered the way Khadija used to ask permission, and that upset him. He said, "O Allah! Hala!" So I became jealous and said, "What makes you remember an old woman amongst the old women of Quraish an old woman (with a teethless mouth) of red gums who died long ago, and in whose place Allah has given you somebody better than her?" - Sahih:Al Bukhari:3821 (islam)