Sunan an-Nasa'i 83
It was narrated from (Aws bin) Abi Aws that his grandfather said:
"I saw the Messenger of Allah (ﷺ) trickle water into his hand until it started to drip from his hand, three times."
أَخْبَرَنَا حُمَيْدُ بْنُ مَسْعَدَةَ، عَنْ سُفْيَانَ، - وَهُوَ ابْنُ حَبِيبٍ - عَنْ شُعْبَةَ، عَنِ النُّعْمَانِ بْنِ سَالِمٍ، عَنِ ابْنِ أَبِي أَوْسٍ، عَنْ جَدِّهِ، قَالَ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم اسْتَوْكَفَ ثَلاَثًا ‏.‏