Mishkat al-Masabih 29 Excellent Qualities and Description of the Prophet كتاب الفضائل والشمائل 126

عَنْ أَنَسِ بْنِ مَالِكٍ أَنَّ أَبَا بَكْرٍ الصّديق رَضِي الله عَنهُ قا ل: نظرتُ إِلى أقدامِ المشركينَ على رؤوسنا وَنَحْنُ فِي الْغَارِ فَقُلْتُ يَا رَسُولَ اللَّهِ لَوْ أَنَّ أَحَدَهُمْ نَظَرَ إِلَى قَدَمِهِ أَبْصَرَنَا فَقَالَ: «يَا أَبَا بَكْرٍ مَا ظَنُّكَ بِاثْنَيْنِ اللَّهُ ثالثهما» مُتَّفق عَلَيْهِ

Anas b. Malik told that Abu Bakr as-Siddiq said: I looked at the feet of the polytheists above our heads when we were in the cave and said, “Messenger of God, if one of them were to look at his foot he would see us.” He replied, “Abd Bakr, what do you think of two people along with whom God makes a third?” (Bukhari and Muslim.)