What does Luke 10:4 mean?

Jesus is sending out seventy-two disciples—not including the Twelve (Matthew 10:2–4)—to prepare towns for His arrival. They will heal, cast out demons, and announce that the kingdom of God is coming (Luke 10:1–3, 9, 17). Earlier, when Jesus sent out the Twelve, He told them, "Take nothing for your journey, no staff, nor bag, nor bread, nor money; and do not have two tunics" (Luke 9:3). The instructions for the seventy-two are basically the same: take only the clothes they're wearing and leave behind everything else they may need.

Their lack of moneybag differentiates them from the traveling teachers and magicians who expect to be paid for their services. These men also take knapsacks to hold supplies as they travel from town to town. "No sandals" may mean the disciples are to go barefoot, but likely means they are not to take a backup pair; like the children of Israel who traveled through the wilderness for forty years, they need to trust that God will ensure their clothes will not wear out (Deuteronomy 29:5).

In fact, their entire mission is to be characterized by a dependence on God, starting with the prayer that God will send more messengers (Luke 10:2). The protection and provision of God gives a visible example of God's coming kingdom.

The command to not greet anyone on the road is not unique. An Old Testament prophet was told not to stop along the way; when he did, he was killed by a lion (1 Kings 13:11–25). God often has specific plans for His followers. In this case, Jesus wants the towns prepared; stopping to talk to other travelers takes time away from the mission (Luke 9:59–62). We need to be mindful when we're being called away from the work Jesus is calling us to do.

During the Last Supper, Jesus will update the instructions. When they travel after His ascension, they are to take money, a bag—perhaps with extra tunics and shoes—and a sword (Luke 22:36). The time of training will be over and they will need to trust in God for far much more than meals and shoes.