Musannaf Ibn Abi Shayba 8:355

Abu Bakr narrated to us, he said: Hatim ibn Isma'il narrated to us, from Ja'far, from his father, from Ali, who said: If he misses the fasting during the ten [days of Dhu al-Hijjah], he should fast [them] at night—he counts them—and he fasts three days [there] and seven when he returns.