Albert Barnes Commentary 1 Kings 8:63

"And Solomon offered for the sacrifice of peace-offerings, which he offered unto Jehovah, two and twenty thousand oxen, and a hundred and twenty thousand sheep. So the king and all the children of Israel dedicated the house of Jehovah." — 1 Kings 8:63 (ASV)

These numbers have been thought incredible, but they are not impossible. At least 100,000 or 120,000 men were assembled (1 Kings 8:65), and as they all offered sacrifice with the king (1 Kings 8:62), the number of victims must have been enormous. Part of the flesh of so many victims would be eaten, but much of the meat may have been privately burned (Leviticus 19:6), the object of the sacrifice being the glory of God and not the convenience of the people. Profusion was a usual feature of the sacrifices of antiquity.