Sahih Muslim
The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wal-Adab)
Book Number: 032 / Hadith Number: 6358
Abu Dharr reported Allah's Messenger (may peace be upon him) commanded me thus: Whenever you prepare a broth, add water to it, and have in your mind the members of the household of your neighbours and then give them out of this with courtesy.