The word(s) "heels" appears 6 time(s) in 5 verse(s) in Quran in Mohsin Khan translation.

(1) Thus We have made you [true Muslims - real believers of Islamic Monotheism, true followers of Prophet Muhammad صلى الله عليه وسلم and his Sunnah (legal ways)], a just (and the best) nation, that you be witnesses over mankind and the Messenger (Muhammad صلى الله عليه وسلم) be a witness over you. And We made the Qiblah (prayer direction towards Jerusalem) which you used to face, only to test those who followed the Messenger (Muhammad صلى الله عليه وسلم) from those who would turn on their heels (i.e. disobey the Messenger). Indeed it was great (heavy) except for those whom Allah guided. And Allah would never make your faith (prayers) to be lost (i.e. your prayers offered towards Jerusalem). Truly, Allah is full of Kindness, the Most Merciful towards mankind.

(2) Muhammad (صلى الله عليه وسلم) is no more than a Messenger, and indeed (many) Messengers have passed away before him. If he dies or is killed, will you then turn back on your heels (as disbelievers)? And he who turns back on his heels, not the least harm will he do to Allah; and Allah will give reward to those who are grateful.

(3) O you who believe! If you obey those who disbelieve, they will send you back on your heels, and you will turn back (from Faith) as losers.

(4) Say (O Muhammad صلى الله عليه وسلم): "Shall we invoke others besides Allah (false deities), that can do us neither good nor harm, and shall we turn back on our heels after Allah has guided us (to true Monotheism)? - like one whom the Shayatin (devils) have made to go astray in the land in confusion, his companions calling him to guidance (saying): 'Come to us.' " Say: "Verily, Allah's Guidance is the only guidance, and we have been commanded to submit (ourselves) to the Lord of the 'Alamin (mankind, jinn and all that exists);

(5) Indeed My Verses used to be recited to you, but you used to turn back on your heels (denying them, and refusing with hatred to listen to them).