[Machine] When Allah's Messenger ﷺ married Umm Salamah, he ordered for a sheep to be slaughtered and then he threw dates and barley upon it. He called people and they ate, and he said that a wedding feast on the first day is a right, on the second day it is customary, and on the third day it is boastful and a matter of reputation. Abu Sa'd Al-Malini, Abu Ahmad ibn 'Adi, Al-Husayn ibn Ismail, Muhammad ibn 'Amr ibn Hayyan, Yahya ibn Sa'id, and Bakr ibn Khunays have all mentioned this narration. However, the reliability of Bakr ibn Khunays is doubted, as people have spoken about him. The narration of Al-Bukhari is also weak. It was narrated from Abu Hurairah in a Marfu' (elevated chain), but it is not reliable. Abu Bakr ibn Ibrahim Al-Farsi mentioned that Ibrahim ibn 'Abdullah narrated from Abu Ahmad ibn Fares, who narrated from Muhammad ibn Ismail Al-Bukhari in a narration of Zuhair ibn 'Uthman, stating that the chain of narrators is not authentic and it is not known to have a reliable companion. Ibn 'Umar and others have mentioned from the Prophet ﷺ that if one of you is invited to a wedding feast, they should accept the invitation and not delay it for more than three days or anything else. This is the most correct view. Ibn Sirin mentioned a story related to this as well.

(Note: The translation is provided to the best of my ability, but some nuances may be lost in translation.  

اللهِ ﷺ لَمَّا تَزَوَّجَ أُمَّ سَلَمَةَ ؓ أَمَرَ بِالنِّطَعِ فَبُسِطَ ثُمَّ أَلْقَى عَلَيْهِ تَمْرًا وَسَوِيقًا فَدَعَا النَّاسَ فَأَكَلُوا وَقَالَ الْوَلِيمَةُ فِي أَوَّلِ يَوْمٍ حَقٌّ وَالثَّانِي مَعْرُوفٌ وَالثَّالِثِ رِئَاءٌ وَسُمْعَةٌ 14513 أَخْبَرَنَا أَبُو سَعْدٍ الْمَالِينِيُّ أنبأ أَبُو أَحْمَدَ بْنُ عَدِيٍّ ثنا الْحُسَيْنُ بْنُ إِسْمَاعِيلَ ثنا مُحَمَّدُ بْنُ عَمْرِو بْنِ حَيَّانَ ثنا يَحْيَى بْنُ سَعِيدٍ عَنْ بَكْرِ بْنِ خُنَيْسٍ فَذَكَرَهُ وَلَيْسَ هَذَا بِقَوِيٍّ بَكْرُ بْنُ خُنَيْسٍ تَكَلَّمُوا فِيهِ وَحَدِيثُ الْبَكَّائِيِّ أَيْضًا غَيْرُ قَوِيٍّ وَرُوِيَ ذَلِكَ عَنْ أَبِي هُرَيْرَةَ مَرْفُوعًا وَلَيْسَ بِشَيْءٍ 14514 وَأَخْبَرَنَا أَبُو بَكْرِ بْنُ إِبْرَاهِيمَ الْفَارِسِيُّ أَنْبَأَ إِبْرَاهِيمُ بْنُ عَبْدِ اللهِ ثنا أَبُو أَحْمَدَ بْنُ فَارِسٍ عَنْ مُحَمَّدِ بْنِ إِسْمَاعِيلَ الْبُخَارِيِّ فِي حَدِيثِ زُهَيْرِ بْنِ عُثْمَانَ قَالَ لَمْ يَصِحَّ إِسْنَادُهُ وَلَا يُعْرَفُ لَهُ صُحْبَةٌ وَقَالَ ابْنُ عُمَرَ وَغَيْرُهُ عَنِ النَّبِيِّ ﷺ إِذَا دُعِيَ أَحَدُكُمْ إِلَى الْوَلِيمَةِ فَلْيُجِبْ وَلَمْ يَخُصَّ ثَلَاثَةَ أَيَّامٍ وَلَا غَيْرَهَا وَهَذَا أَصَحُّ وَذَكَرَ حِكَايَةَ ابْنِ سِيرِينَ