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: 6204
Anas b. Malik reported: I heard Allah's Messenger (may peace be upon him) as saying: He who is desirous that his means of sustenance should be expanded for him or his age may be lengthened, should join the tie of relationship.