وَعَنْ زَيْدِ بْنِ أَسْلَمَ أَنَّهُ قَالَ: شَرِبَ عمر بن الْخطاب لَبَنًا وَأَعْجَبَهُ وَقَالَ لِلَّذِي سَقَاهُ: مَنْ أَيْنَ لَكَ هَذَا اللَّبَنُ؟ فَأَخْبَرَهُ أَنَّهُ وَرَدَ عَلَى مَاءٍ قَدْ سَمَّاهُ فَإِذَا نَعَمٌ مِنْ نَعَمِ الصَّدَقَةِ وَهُمْ يَسْقُونَ فَحَلَبُوا لِي مِنْ أَلْبَانِهَا فَجَعَلْتُهُ فِي سِقَائِيَ وَهُو هَذَا فَأَدْخَلَ عُمَرُ يَدَهُ فاسْتقاءَه. رَوَاهُ الْبَيْهَقِيّ فِي شعب الْإِيمَان
Zaid b. Aslam said that 'Umar b. al-Khattab drank some milk which pleased him and asked the one who had given him the drink where he had got that milk from. He informed him that he had gone down to a watering-place which he named where there were some of the camels of the sadaqa. The people who were watering the camels had drawn some milk for him which he had put in his milk-skin, and that was what he had given him. ‘Umar then put his hand in his mouth and vomited it. Baihaqi transmitted it in Shu'ab al-iman.
Reported by Malik (No. 609). Cited in Mishkat al-Masabih (No. 2788).