Mishkat al-Masabih 21 Foods كتاب الأطعمة 112

وَعَنْ عَمْرِو بْنِ شُعَيْبٍ عَنْ أَبِيهِ عَنْ جده قَالَ: رَأَيْت رَسُول لله صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَشْرَبُ قَائِمًا وَقَاعِدًا. رَوَاهُ التِّرْمِذِيّ

‘Amr b. Shu’aib, on his father’s authority, said his grandfather told that he saw God’s messenger drink both standing and sitting. Tirmidhi transmitted it.