כָּֽל־הַבְּכ֡וֹר אֲשֶׁר֩ יִוָּלֵ֨ד בִּבְקָרְךָ֤ וּבְצֹֽאנְךָ֙ הַזָּכָ֔ר תַּקְדִּ֖ישׁ לַיהוָ֣ה אֱלֹהֶ֑יךָ לֹ֤א תַעֲבֹד֙ בִּבְכֹ֣ר שׁוֹרֶ֔ךָ וְלֹ֥א תָגֹ֖ז בְּכ֥וֹר צֹאנֶֽךָ׃
Setiap anak sulung jantan yang lahir dari ternak sapimu dan dari kambing dombamu haruslah engkau kuduskan bagi Yang Mahakekal, Allahmu. Janganlah engkau mempekerjakan anak sulung sapimu, dan janganlah engkau menggunting bulu anak sulung kambing dombamu.
Sha'arei Teshuvah
“You must not work your firstling ox or shear your firstling sheep” (Deuteronomy 15:19). [The law of] the firstborn is practiced both in the Land [of Israel] and outside the Land. And a firstling that is mixed in a hundred or [even] a thousand (other animals) renders all of them prohibited in benefit.