וְאֶת־כָּל־חֶלְבּוֹ֙ יַקְטִ֣יר הַמִּזְבֵּ֔חָה כְּחֵ֖לֶב זֶ֣בַח הַשְּׁלָמִ֑ים וְכִפֶּ֨ר עָלָ֧יו הַכֹּהֵ֛ן מֵחַטָּאת֖וֹ וְנִסְלַ֥ח לֽוֹ׃ (פ)
And all the fat thereof shall he make smoke upon the altar, as the fat of the sacrifice of peace-offerings; and the priest shall make atonement for him as concerning his sin, and he shall be forgiven.
Read kabbalistic (mystical) interpretation of Leviticus 4:26: and classical mystical sources.