Musannaf Ibn Abi Shayba 37:260

Abu Mu'awiyah narrated to us, he said: Al-A'mash narrated to us, from Salam Abu Sharhabil, from Abu Harthamah, who said: A sheep of his dropped droppings, so he said to a slave girl of his: "O Jarda', this dropping has reminded me of a hadith I heard from the Commander of the Faithful. I was with him at Karbala, and he passed by a tree under which there were gazelle droppings. He took a handful of them and smelled them, then said: 'Seventy thousand will be gathered from this back [i.e., this land/place], entering Paradise without reckoning.'"