Musnad Ahmad 5:779

Muhammad ibn Ubayd narrated to us, Hashim—meaning Ibn al-Barid—narrated to us, from Isma'il al-Hanafi, from Muslim al-Batin, from Abu 'Abd al-Rahman al-Sulami, who said: 'Ali (may Allah be pleased with him) took my hand, and we set out walking until we sat on the bank of the Euphrates. 'Ali (may Allah be pleased with him) said: The Messenger of Allah (may Allah bless him and grant him peace) said: "There is no soul that is breathed into except that its misery or happiness has already been decreed for it by Allah." A man stood up and said: O Messenger of Allah, then why should we act? He said: "Act, for everyone is facilitated for that which he was created for." Then he recited this verse: {As for he who gives and fears Allah, and believes in the best [reward], We will ease him toward ease. But as for he who withholds and considers himself free of need, and denies the best [reward], We will ease him toward difficulty.}