The repeated theme in these chapters is that there is a warfare that is the LORD’s warfare. Moses was commanded by the LORD to take vengeance on the Midianites (Num 31:2). Moses even told the children of Israel, that they were to take vengeance for the LORD on Midian (Num 31:3).
“And they warred against the Midianites, just as the LORD commanded Moses, and they killed all the males.” Num 31:7
The country which was east of the Jordan, the kingdoms of the Amorites, was the country which the LORD defeated before the congregation of Israel (Num 32:4). Because Caleb and Joshua were willing to enter the land armed for war 38 years previously, and encouraged the children of Israel to enter the land armed for war, Moses said of them that they had wholly followed the LORD (Num 32:12). When Moses thought that Reuben and Gad wanted to opt out of the warfare of possessing the land, he warned them that they would be turning away from following the LORD (Num 32:15).
Then Moses said to them, “If you do this thing, if you arm yourselves before the LORD for the war, and all your armed men cross over the Jordan before the LORD until He has driven out His enemies from before Him, and the land is subdued before the LORD, then afterward you may return and be blameless before the LORD … But if you do not do so, then take note, you have sinned against the LORD; and be sure your sin will find you out.” Num 32:20-23
In fact it would be sin for Reuben and Gad to not cross over armed with Israel, to drive out, not Israel’s enemies, but the LORD’s enemies from before Him!
Now the LORD has reconciled the world to Himself, in the blood of Messiah Yeshua our Lord, but enemies to the LORD remain, who are not flesh and blood, but principalities, powers, rulers of the darkness of this age, and spiritual hosts of wickedness in the heavenly places (Eph 6:10-18). God has given us armor and weapons, which are sharper than any two edged sword, and has already defeated His enemies before Him! But we must gird up, and cross over, and do battle, and not shrink back from following Him!
“And as for you, remain outside the camp seven days; whoever has killed any person, and whoever has touched any slain, purify yourselves and your captives on the third day and on the seventh day.” Num 31:19
The law of purification from uncleanness on the third and seventh days is referring back to the law of the red heifer for purification (Num 19:19-20)! We have already seen that the law of the red heifer is prophetic of Messiah Yeshua. Now what is significant about the third and seventh days in purification?
Of course, the third day is the day Messiah rose from the dead with resurrection life, and completely defeated death! Therefore we are cleansed from death on the third day! And I believe the seventh day is a reference to the law of the Sabbath, which is also the gospel of grace preached from Torah! The seventh day is the day of rest from work, just as in the gospel, we rest in the cleanness Messiah Yeshua has imputed to us, and do not work our own work to earn salvation! Also, the seventh millennium is the millennium of the kingship of Messiah Yeshua, a millennium of rest and cleanness from sin!