וְהִקְרִיב֙ מִזֶּ֣בַח הַשְּׁלָמִ֔ים אִשֶּׁ֖ה לַיהוָ֑ה אֶת־הַחֵ֙לֶב֙ הַֽמְכַסֶּ֣ה אֶת־הַקֶּ֔רֶב וְאֵת֙ כָּל־הַחֵ֔לֶב אֲשֶׁ֖ר עַל־הַקֶּֽרֶב׃
And he shall present of the sacrifice of peace-offerings an offering made by fire unto the LORD: the fat that covereth the inwards, and all the fat that is upon the inwards,
Read kabbalistic (mystical) interpretation of Leviticus 3:3: and classical mystical sources.