מִמַּֽחֲצִיתָ֖ם תִּקָּ֑חוּ וְנָתַתָּ֛ה לְאֶלְעָזָ֥ר הַכֹּהֵ֖ן תְּרוּמַ֥ת יְהוָֽה׃
take it of their half, and give it unto Eleazar the priest, as a portion set apart for the LORD.
Read kabbalistic (mystical) interpretation of Numbers 31:29: and classical mystical sources.