Midrash for Sanhedrin 104:24

רבי יונתן אומר לא מפני שהיא קלה אלא כל מיתה האמורה בתורה סתם אינה אלא חנק

just as there, it is done with a sword and at the neck, so here too, execution is with the sword and at the neck [i.e., the throat]. If so, just as there it was done with an axe, and on the nape of the neck, so here too? — R. Nahman answered in the name of Rabbah b. Abbuha: Scripture saith: <i>But thou shalt love thy neighbour as thyself</i>:<span class="x" onmousemove="('comment',' Lev. XIX, 18. ');">²²</span>

Sifrei Devarim