The Prophet ﷺ called for water in a wide, shallow vessel, then placed his fingers into it. Water began to gush forth from between his fingers, and the people started performing ablution from it. The people kept performing ablution, and I estimated their number to be between seventy and eighty.
حدثنا يونس حدثنا حماد يعني ابن زيد عن ثابت
أن النبي ﷺ دعا بماء في قدح رحراح فوضع رسول الله ﷺ أصابعه في القدح فجعل الماء ينبع وجعل القوم يتوضئون منه ويخرج من بين أصابعه قال وجعل القوم يتوضئون قال فحزرت القوم فإذا ما بين السبعين إلى الثمانين
Its isnad is sahih, and the hadith has already been mentioned. It is found in Bukhari 6/581, no. 3574, Fath, in the chapters on virtues and the signs of prophethood, and Tirmidhi 5/596, no. 3631, who graded it sahih.