Negative commandment · Lo Ta’aseh #94 of 613
That we not incinerate the entrails of animals with blemishes
שלא להקטיר אימורי בעלי מומין
The verse · Vayikra 22:22
עַוֶּרֶת אוֹ שָׁבוּר אוֹ־חָרוּץ אוֹ־יַבֶּלֶת אוֹ גָרָב אוֹ יַלֶּפֶת לֹא־תַקְרִיבוּ אֵלֶּה לַה׳ וְאִשֶּׁה לֹא־תִתְּנוּ מֵהֶם עַל־הַמִּזְבֵּחַ לַה׳
“Blind, or broken, or maimed, or having a growth, or scurvy, or scabbed, you shall not offer these to the Lord, nor make an offering by fire of them upon the altar to the Lord.”
The Rambam’s words
Not to burn the sacrificial portions of animals with disqualifying physical blemishes [as sacrifices on the altar], as [Leviticus 22:22] states: "Do not make a fire offering of them."
שלא להקטיר אימורי בעלי מומין, שנאמר "ואישה, לא תיתנו מהם" (ויקרא כב,כב).
Who & when
“However we should not count this prohibition with those that are practiced today; as due to our iniquities, we do not have an altar upon which to incinerate.”
Where in the Mishneh Torah
Hilchot Things Forbidden on the Altar הלכות איסורי המזבח