Musnad Ahmad 750:4

Husayn ibn Ali narrated to us, from Za'idah, from al-Rukayn, from his father, from Yasir ibn 'Amilah, from Khuraym ibn Fatik, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever spends an expenditure in the way of Allah, it shall be multiplied seven hundred times."