Musnad Abu Ya'la al-Mawsili 159:12

Abu Khaythama narrated to us, Sufyan narrated to us, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah, attributing it to the Prophet (may Allah bless him and grant him peace), who said: Allah, Blessed and Exalted is He, says: "O son of Adam, spend, and I will spend on you." And He said: "The Right Hand of Allah is full, overflowing; nothing diminishes it, neither night nor day."