Remembering. God wanted Israel to remember what His hand had done for them (vv. 3, 9, 14, 16), lest in the future they forget to trust Him and serve Him. The setting apart of the firstborn would remind them that the firstborn sons of Israel had been redeemed by the Lord. The annual Passover would remind them to keep their lives pure. When you consider that Jesus Christ has redeemed us by His blood, surely we should give ourselves to Him and obey His Word.
Instructing. The younger generation cannot know the works of the Lord unless the older generation tells them. The Word of God must control our lips (v. 9), our eyes, and our hands (v. 16), and we must share it with others. The Jews took this literally and wore portions of the Law on the forehead and hand, but the Lord was surely speaking in a metaphorical way.
Following. God frees us from bondage, and He also guides us to the inheritance He has prepared for us. His Word is like that pillar of cloud and fire, and He will show us the way if we will trust Him.
