Abu Bakr said, "I saw the feet of the polytheists right above our heads while we were in the cave. I said, 'Messenger of Allah, if any one of them were to look down at his feet, he would see us beneath them.'He replied, 'Abu Bakr, what do you think of two whose third is Allah?'"
نظرت إلى أقدام المشركين على رؤوسنا، ونحن في الغار، فقلت: يا رسول الله! لو أن أحدهم نظر إلى قدميه، أبصرنا تحت قدميه. فقال: يا أبا بكر ما ظنك باثنين الله ثالثهما.
Bukhari reported it in the tafsir (4663), and Muslim reported it in the virtues of the companions (2381), both through the route of Habban bin Hilal, who said, Hammam narrated to us, who said, Thabit narrated to us, who said, Anas bin Malik narrated to us, that Abu Bakr Siddiq told him, he said, then he related it. The wording given here is Muslim's.In Abu Bakr's statement, "If one of them had looked at his feet, he would have seen us," there is evidence that the story of the spider weaving its web over the mouth of the cave is not sound, for otherwise the two of them would have been safe and secure because of the web's presence. See the discussion of the hadith about the spider's weaving in the biography of the Prophet.