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tabarani:4073

[Machine] And about the Prophet ﷺ that he was asked about Shafa' and Witr (prayers). So he said, "Two days and one night - the day of Arafah and the day of sacrifice. And Witr is the night of sacrifice, the night of gathering."  

الطبراني:٤٠٧٣

وَعَنِ النَّبِيِّ ﷺ أَنَّهُ سُئِلَ عَنِ الشَّفْعِ وَالْوَتْرِ؟ فَقَالَ يَوْمَانِ وَلَيْلَةٌ يَوْمُ عَرَفَةَ وَيَوْمُ النَّحْرِ وَالْوِتْرُ لَيْلَةُ النَّحْرِ لَيْلَةُ جَمْعٍ