Jerusalem Talmud Sanhedrin 7.4

משנה: מִצְוַת הַנֶּחֱנָקִין הָיוּ מְשַׁקְּעִין אוֹתוֹ בַּזֶּבֶל עַד אַרְכּוּבּוֹתָיו. וְנוֹתְנִין סוּדָרִין קָשָׁה לְתוֹךְ הָרַכָּה וְכוֹרֵךְ עַל צַוָּארוֹ. זֶה מוֹשֵׁךְ אֶצְלוֹ וְזֶה מוֹשֵׁךְ אֶצְלוֹ עַד שֶׁנַּפְשׁוֹ יוֹצְאָה:

MISHNAH: The order of the strangled: One makes him sink into manure up to his knees, puts a stiff cloth into soft ones and winds them around his throat. One person draws in his direction, the other one draws in his direction until he expires.

הלכה: מִצְוַת הַנֶּחֱנָקִין כול׳. חֶנֶק לֵית מַשְׁכַּח. אָמְרָת. הֲרֵי זוֹ מִיתָה בַתּוֹרָה. וְכָל מִיתָה שֶׁנֶּאֶמְרָה בַתּוֹרָה סְתָם אֵין אַתְּ רַשַּׁאי לְמוֹשְׁכָהּ לְהַחֲמִיר עָלֶיהָ אֶלָּא לָהָקֵל עָלֶיהָ. דִּבְרֵי רִבִּי יֹאשִׁיָּה. אָמַר לוֹ רִבִּי יוֹנָתָן. לֹא מִפְּנֵי שֶׁהִיא קַלָּה אֶלָּא שֶׁנֶּאֶמְרָה סְתָם. וְכָל מִיתָה שֶׁנֶּאֶמְרָה סְתָם אֵי אַתָּה רַשַּׁאי לְהַחֲמִיר עָלֶיהָ אֶלָּא לָהָקֵל עָלֶיהָ. תָּלוּ אוֹתוֹ בַּחֶנֶק.

HALAKHAH: “The order of the strangled,” etc. Strangling? You do not find it. This refers to death penalty in the Torah. For any death penalty mentioned in the Torah with no particular indication, you are not empowered to try to make it more stringent, only to make it less so, the words of Rebbi Josia. Rebbi Jonathan said to him, not because it is the least painful, but because it is mentioned in the Torah with no specific indication. For any death penalty mentioned in the Torah with no particular indication, you are not empowered to try to make it more stringent but only to make it less so; they ascribed this to strangling.

אָמַרְתָּ. סֵדֶר חֶנֶק כָּךְ הוּא. זֶה מוֹשֵׁךְ אֶצְלוֹ וְזֶה מוֹשֵׁךְ אֶצְלוֹ. כַּהֲנָא בְעָא קוֹמֵי רַב. תַּמָּן אַתָּ מַר. זֶה מוֹשֵׁךְ הֵילָךְ וְזֶה מוֹשֵׁךְ הֵילָךְ. וָכָא אַתָּ מַר. זֶה מוֹשֵׁךְ אֶצְלוֹ וְזֶה מוֹשֵׁךְ אֶצְלוֹ. אָמַר לֵיהּ. תַּמָּן זֶה מִלְּפָנָיו וְזֶה מִלְּאַחָרָיו. בְּרַם הָכָא דֵּין מִן דֵּין סִיטְרָא וְדֵין מִן דֵּין סִיטְרָא.

You said, the order of strangling is the following: “One person draws in his direction, the other one draws in his direction.” Cahana asked before Rav: There, you say, “one draws in one direction, the other draws in one direction.” But here, you say, “one draws in his direction, the other draws in his direction.” He told him, there one is in front, the other in the back. But here, one is on one side, the other one is on the other side.