Abdullah bin Uthman al-Thaqafi (may Allah have mercy on him) narrates from a one-eyed man of Thaqif who was always spoken of with praise; if his name is not Zuhayr bin Uthman, then I do not know his name, that the Prophet (peace and blessings be upon him) said: "The wedding feast (walimah) on the first day is a right, on the second day it is a kindness, and on the third day it is for reputation and showing off."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14509
When Sa'id bin al-Musayyib (may Allah have mercy on him) was invited to a wedding feast (walimah) on the first or second day, he would accept, but on the third day he would not accept, and he would say: This is for reputation and showing off.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14510
Qatadah (may Allah have mercy on him) said: Ibn al-Musayyib (may Allah have mercy on him) would accept the invitation to a wedding feast (walimah) on the first and second days, but on the third day he threw pebbles at them and said: "Go away, you people of showing off and reputation."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14511
Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "The food of the wedding feast (walimah) on the first and second days is a right." In the narration of al-Sulami: "The food of one day is a right, the food of two days is a Sunnah, and the food of the third day is showing off and reputation; and whoever seeks reputation, Allah will expose him." Al-Sulami did not mention the word "showing off".
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14512
Bakr bin Khunays also mentioned it (through another chain).
This is not strong; Bakr bin Khunays has been criticised, and the hadith of al-Bakka'i is also not strong. It has also been narrated from Abu Hurayrah as a saying of the Prophet (marfu'), and it is worth nothing.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14513
Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) and others narrate from the Prophet (peace and blessings be upon him): "Whenever one of you is invited to a wedding feast (walimah), let him accept," and he (peace and blessings be upon him) did not specify three days or anything else.
Al-Bukhari said about the hadith of Zuhayr bin Uthman: Its chain is not authentic, and he is not known to have been a Companion; and this (hadith of Ibn Umar) is more authentic.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14514
Hafsah (bint Sirin) (may Allah have mercy on her) said: Sirin married in Madinah and fed the people a wedding feast (walimah) for seven days. He had also invited Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him); he was fasting, so he came, supplicated for blessing, and left.
Hammad bin Zayd (may Allah have mercy on him) narrates it from Ayyub (may Allah have mercy on him), but he did not mention Hafsah. Ma'mar narrated from Ayyub: eight days; but the first is more authentic.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14515
Hadith Gradingمحدثین:صحيح
Hadith Takhrij«صحيح۔ اخرجه الفسوي في معرفه 3/ 140»
Ibn Sirin (may Allah have mercy on him) said: On the occasion of his marriage my father invited the people to food for eight days. He had also invited Sayyiduna Ubayy bin Ka'b (may Allah be pleased with him), who was fasting on the day he came. He made a supplication, that is, he supplicated for blessing, and then left.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14516