Hadith 1292
Sayyiduna Jabir bin Abdullah (may Allah be pleased with him) narrates from the Messenger of Allah (peace and blessings be upon him) that he (peace be upon him) said: "Whoever has a well dug from which living beings—jinn, humans, and birds—drink, Allah Almighty will grant him reward on the Day of Resurrection. And whoever builds a mosque the size of a sparrow's nest or even smaller, Allah Almighty will build a house for him in Paradise." The words of Yunus are: "Whatever beast or bird drinks from it—" and he said: "A mosque the size of a sparrow's nest."