John Wesley on Matthew 12:4

He entered into the house of God - Into the tabernacle. The temple was not yet built. The show bread - So they called the bread which the priest, who served that week, put every Sabbath day on the golden table that was in the holy place, before the Lord. The loaves were twelve in number, and represented the twelve tribes of Israel: when the new were brought, the stale were taken away, but were to be eaten by the priests only. 1Sam 21:6.