The word(s) "necks" appears 13 time(s) in 13 verse(s) in Quran in Mohsin Khan translation.

(11) Then he said "Bring them (horses) back to me." Then he began to pass his hand over their legs and their necks (till the end of the display).

(12) When iron collars will be rounded over their necks, and the chains, they shall be dragged along,

(13) So, when you meet (in fight - Jihad in Allah's Cause) those who disbelieve, smite (their) necks till when you have killed and wounded many of them, then bind a bond firmly (on them, i.e. take them as captives). Thereafter (is the time) either for generosity (i.e. free them without ransom), or ransom (according to what benefits Islam), until the war lays down its burden. Thus [you are ordered by Allah to continue in carrying out Jihad against the disbelievers till they embrace Islam and are saved from the punishment in the Hell-fire or at least come under your protection], but if it had been Allah's Will, He Himself could certainly have punished them (without you). But (He lets you fight) in order to test some of you with others. But those who are killed in the Way of Allah, He will never let their deeds be lost.