The Priest Then Takes the Jealousy Offering Of barley Grain From the Hand of the Woman (Numbers 5:25)
‘And the priest shall take the grain offering of jealousy out of the woman's hand, and shall wave the grain offering before Yahweh, and bring it to the altar,'
Then before she drank the liquid the priest was to take the grain offering for jealousy from the woman's hand and wave it before Yahweh and bring it to the altar. The waving before Yahweh demonstrated that His attention had been drawn to it, and that it was being given to Him.