Musannaf Ibn Abi Shaybah

Hazrat Muhammad bin Ishaq (may Allah have mercy on him) says that I asked Hazrat Abu Bakr bin Muhammad bin Amr bin Hazm (may Allah have mercy on him) about the enclosure of a well. He replied: In the time of ignorance, the area around it was fifty cubits, and between two wells it was one hundred cubits. When the era of Islam came, it was observed that less than this was also sufficient, so then for each well it was made twenty-five cubits, and for its surrounding area, fifty cubits.