וְכָל־מַעְשַׂ֤ר בָּקָר֙ וָצֹ֔אן כֹּ֥ל אֲשֶׁר־יַעֲבֹ֖ר תַּ֣חַת הַשָּׁ֑בֶט הָֽעֲשִׂירִ֕י יִֽהְיֶה־קֹּ֖דֶשׁ לַֽיהוָֽה׃
And all the tithe of the herd or the flock, whatsoever passeth under the rod, the tenth shall be holy unto the LORD.
Read kabbalistic (mystical) interpretation of Leviticus 27:32: and classical mystical sources.