Leviticus 14:51

And he shall take the cedar wood, and the hyssop, and the scarlet, and the living bird, and dip them in the blood of the slain bird, and in the running water, and sprinkle the house seven times:

Cross-reference

Leviticus 14:6 describes dipping the living bird in blood for personal cleansing, identical to the house ritual here.

Leviticus 14:7 also sprinkles seven times and releases the living bird, exactly paralleling the house cleansing.

2 Kings 5:10 commands washing seven times for Naaman's leprosy, echoing the sevenfold sprinkling for house cleansing.

Hebrews 9:22 states that blood purifies under the law, underlying the blood sprinkling for the house.