Musnad Ahmad 750:2

Mu'awiyah ibn 'Amr narrated to us, Zaidah narrated to us, al-Rukayn ibn al-Rabi' ibn 'Amilah al-Fazari narrated to us, from his father, from Yasir ibn 'Amilah, from Khuraym ibn Fatik al-Asadi, from the Prophet, peace and blessings of Allah be upon him, who said: "Whoever spends an expenditure in the way of Allah, it is written for him as seven hundred times."