Sahih al-Bukhari 3575

Narrated Humaid: Anas bin Malik said, "Once the time of the prayer became due and the people whose houses were close to the Mosque went to their houses to perform ablution, while the others remained (sitting there). A stone pot containing water was brought to the Prophet, who wanted to put his hand in it, but It was too small for him to spread his hand in it, and so he had to bring his fingers together before putting his hand in the pot. Then all the people performed the ablution (with that water)." I asked Anas, "How many persons were they." He replied, "There were eighty men."