Burayda reported,

A group of men from the Ansar said to Ali, "Fatimah is available for you to marry."So Ali went to the Messenger of Allah ﷺ, who asked, "What does the son of Abu Talib need?"Ali replied, "I have come to mention Fatimah, daughter of Muhammad, Messenger of Allah ﷺ."The Prophet ﷺ said, "Welcome and greetings," adding nothing more than that.Ali then went out to the group of Ansar who were waiting for him.They asked, "What news do you bring?"He answered, "I do not know, except that he said to me, 'Welcome and greetings.'"They said, "Either one of those words from the Messenger of Allah ﷺ is enough for you. He has given you family, and he has given you welcome."Then, after the Prophet ﷺ had married him to her, he said, "Ali, the bridegroom must have a wedding feast."Saad said, "I have a ram," and a group of the Ansar gathered several measures of corn for him.On the night of the consummation, the Prophet ﷺ said, "Do not do anything until you meet me."Then the Messenger of Allah ﷺ called for a vessel, performed ablution from it, and then poured what remained over Ali, saying, "O Allah, bless them both, send blessings upon them, and bless them in their offspring."

عن بريدة قال

قال نفر من الأنصار لعلي: عندك فاطمة. فأتى رسول الله ﷺ فقال: ما حاجة ابن أبي طالب؟ قال: ذكرت فاطمة بنت محمد رسول الله ﷺ قال: مرحبا. وأهلا. لم يزده عليهما. فخرج علي على أولئك الرهط من الأنصار ينتظرونه. قالوا: ما وراءك؟ قال: ما أدري غير أنه قال لي: مرحبا وأهلا. قالوا: يكفيك من رسول الله ﷺ إحداهما. أعطاك الأهل أعطاك المرحب، فلما كان بعدما زوجه قال: يا علي إنه لا بد للعروس من وليمة فقال سعد: عندي كبش، وجمع له رهط من الأنصار أصعا من ذرة. فلما كان ليلة البناء قال: لا تحدث شيئا حتى تلقاني. قال: فدعا رسول الله ﷺ بإناء فتوضأ منه، ثم أفرغه على علي، ثم قال: اللهم بارك فيهما، وبارك عليهما وبارك لهما في نسلهما.