Musnad Ahmad 457:48

Muhammad ibn Ja'far and Bahz narrated to us, they said: Shu'bah narrated to us, from 'Adi ibn Thabit, he said: I heard 'Abdullah ibn Yazid al-Ansari narrating from Abu Mas'ud—Bahz said: al-Badri—from the Prophet, may Allah bless him and grant him peace, that he said: "Indeed, when a Muslim spends an expenditure upon his family while he seeks its reward, it is for him a charity."