לֹא־תִזְבַּח֩ לַיהוָ֨ה אֱלֹהֶ֜יךָ שׁ֣וֹר וָשֶׂ֗ה אֲשֶׁ֨ר יִהְיֶ֥ה בוֹ֙ מ֔וּם כֹּ֖ל דָּבָ֣ר רָ֑ע כִּ֧י תוֹעֲבַ֛ת יְהוָ֥ה אֱלֹהֶ֖יךָ הֽוּא׃ (ס)
Thou shalt not sacrifice unto the LORD thy God an ox, or a sheep, wherein is a blemish, even any evil thing; for that is an abomination unto the LORD thy God.
The Five Books of Moses, by Everett Fox
The Five Books of Moses, by Everett Fox
Related to 15:21, the text reiterates that YHWH must be worshiped only in perfection—meaning that a sacrificial animal must be free of defects.