Halakhah for Makkot 3:12
כֵּיצַד מַלְקִין אוֹתוֹ, כּוֹפֵת שְׁתֵּי יָדָיו עַל הָעַמּוּד הֵילָךְ וְהֵילָךְ, וְחַזַּן הַכְּנֶסֶת אוֹחֵז בִּבְגָדָיו, אִם נִקְרְעוּ נִקְרָעוּ, וְאִם נִפְרְמוּ נִפְרָמוּ, עַד שֶׁהוּא מְגַלֶּה אֶת לִבּוֹ. וְהָאֶבֶן נְתוּנָה מֵאַחֲרָיו, חַזַּן הַכְּנֶסֶת עוֹמֵד עָלֶיהָ. וּרְצוּעָה שֶׁל עֵגֶל בְּיָדוֹ, כְּפוּלָה אֶחָד לִשְׁנַיִם וּשְׁנַיִם לְאַרְבָּעָה, וּשְׁתֵּי רְצוּעוֹת עוֹלוֹת וְיוֹרְדוֹת בָּהּ:
How is he smitten? His two hands are tied on either side to a post [stuck standing in the ground and high enough to lean upon], and the beadle of the congregation [the deputy of beth-din] takes hold of his garments. If they are torn, they are torn; and if they are rent [at the seam], they are rent — until he exposes his heart. And the stone is placed behind him [the one to be smitten.] The beadle of the congregation stands upon it with the thong of a calf in his hand, [it being written (Deuteronomy 25:3): "Forty shall he smite him," followed by (4): "You shall not muzzle an ox in its threshing."], doubled, one to two and two to four, [i.e., four thongs sewn one atop the other], and two [thin] thongs of an ass, running up and down through it [as a saddle band. The rationale: It is written (Isaiah 1:3): "The ox knows its owner, and the ass, its master's crib." The Holy One Blessed be He said: "Let that (the ass) which recognizes its master's crib come and exact punishment of him who did not recognize his Master's crib."]