Musannaf Ibn Abi Shayba 36:256

Katheer ibn Hisham narrated to us, he said: al-Dastawa’i narrated to us, from Abu al-Zubayr, from Jabir, who said: A cry went out regarding our dead on the day of Uhud when Mu’awiyah diverted the spring, so we exhumed them after forty years. Their bodies were soft, and their limbs were flexible.