לֹֽא־תִזְבַּ֥ח עַל־חָמֵ֖ץ דַּם־זִבְחִ֑י וְלֹֽא־יָלִ֥ין חֵֽלֶב־חַגִּ֖י עַד־בֹּֽקֶר׃
Thou shalt not offer the blood of My sacrifice with leavened bread; neither shall the fat of My feast remain all night until the morning.
Read kabbalistic (mystical) interpretation of Exodus 23:18: and classical mystical sources.