Musnad Abu Ya'la al-Mawsili 3:298

Ubayd Allah ibn Umar narrated to us, Yusuf ibn Khalid narrated to us, Harun ibn Sa'd narrated to us, from Abu Salih al-Hanafi, from Ali, who said: The Messenger of Allah (may Allah bless him and grant him peace) commanded me to fill in their wells—meaning on the day of Badr.