Exodus 18 presents a type, a portrait, of the kingdom of God, in which the tabernacle, God’s dwelling place, was built. The fact that this portrait is presented after the war against Amalek signifies that when the flesh as God’s enemy is dealt with, the kingdom with the kingship immediately comes in (cf. Gal. 5:17-25), and the church as the Body of Christ is built up (cf. 1 Kings chs. 1—8). In order to realize the kingdom with the building of the church, we must utterly repudiate the flesh in both its good and evil aspects (cf. Phil. 3:3-10). Saul lost the kingship because he did not utterly destroy Amalek but spared the best of what was to be destroyed (1 Sam. 15 and notes).
According to historical sequence, the events described in ch. 18 took place after the building of the tabernacle and not long before the children of Israel began their journey with the tabernacle toward the good land (Deut. 1:6-18). Under divine inspiration Moses inserted these events after ch. 17 to show that in the experience of God’s full salvation the kingdom comes after God’s people have been delivered from Satan (Pharaoh) and the world (Egypt), and after the flesh (Amalek) has been defeated and subdued. After the defeat of Amalek, the kingdom is needed as the sphere, the environment, for the building up of God’s dwelling place on earth.