כֹּ֚ל חֵ֣לֶב יִצְהָ֔ר וְכָל־חֵ֖לֶב תִּיר֣וֹשׁ וְדָגָ֑ן רֵאשִׁיתָ֛ם אֲשֶׁר־יִתְּנ֥וּ לַֽיהוָ֖ה לְךָ֥ נְתַתִּֽים׃
All the best of the oil, and all the best of the wine, and of the corn, the first part of them which they give unto the LORD, to thee have I given them.
Read halakhic rulings (Jewish law) on Numbers 18:12: and classical halakhic sources.