Positive commandment · Mitzvat Aseh #68 of 613
For the [High] Court to offer a sacrifice if it renders an erroneous decision
להקריב בית דין קרבן אם טעו בהוראה
The verse · Vayikra 4:13
וְאִם כׇּל־עֲדַת יִשְׂרָאֵל יִשְׁגּוּ וְנֶעְלַם דָּבָר מֵעֵינֵי הַקָּהָל וְעָשׂוּ אַחַת מִכׇּל־מִצְוֺת ה׳ אֲשֶׁר לֹא־תֵעָשֶׂינָה וְאָשֵׁמוּ
“And if the whole congregation of Yisra᾽el sin through ignorance, and the thing be hid from the eyes of the assembly, and they have done something against any of the commandments of the Lord concerning things which should not be done, and have incurred guilt;”
The Rambam’s words
For the [High] Court to offer a sacrifice if it renders an erroneous decision, as [Leviticus 4:13] states: "If the entire congregation of Israel shall err...."
להקריב בית דין קרבן אם טעו בהוראה, שנאמר: "וְאִם כָּל עֲדַת יִשְׂרָאֵל יִשְׁגּוּ" (ויקרא ד, יג).
Who & when
“And [it] is practiced at the time of the [Temple] when we have Great Sanhedrins.”
Where in the Mishneh Torah
Hilchot Offerings for Unintentional Transgressions הלכות שגגות