Riyad as-Salihin 81

When Messenger of Allah (sallallahu alayhi wa sallam) and I were in the cave of Thaur and I saw the feet of the polytheists who were above us at the mouth of the cave (on the eve of the Emigration), I submitted: “O Messenger of Allah! If one of them were to look down below his feet, he would see us”. He (sallallahu alayhi wa sallam) said, “O Abu Bakr! What do you think of two whose third is Allah”.