The Priest Bring the Man's Offering of Memorial Before Yahweh and Burns It On The Altar. Then He Makes Her Drink the Water (Numbers 5:26).
‘And the priest shall take a handful of the grain offering, as its memorial, and burn it on the altar, and afterwards he shall make the woman drink the water.'
The priest would then offer a memorial portion of the grain offering directly to Yahweh by burning it on the altar, after which he would make the woman drink the water. The grain offering was seen as directly drawing Yahweh's attention to the situation, and its quality would indicate the decision that had to be made. Was she innocent or not? The woman would know that if she was innocent the offering would act as an atoning sacrifice. If she was guilty it would call on her the wrath of God for a false offering, caused because she had not confessed her guilt. Everything was now left in the hands of Yahweh.
“A handful of the grain offering, as its memorial.” Compare ‘the grain offering for memorial' in Numbers 5:15. The handful represented a ‘drawing attention to' (memorial) of the whole.