“I will make you pass under the shepherd’s staff.” A shepherd counted his sheep for different reasons and he would count them by passing them under his staff. The shepherd or herdsman drove the flock or herd through a gate, and someone counted the animals as they went through. In the case of the tithe, every tenth animal passing under the rod would be marked because each tenth newborn animal was given to God as His tithe. If a person was starting out with a small herd or flock, and ten animals were not born to him that year, then the man did not have to tithe that year, which was a way God provided for His people and helped them build their wealth (Lev. 27:30-33).
Ezekiel 20:37 is a picture of God gathering His faithful people together and counting them to make sure none of them is missing, as well as separating them into good and bad. God’s people have sinned and will suffer consequences, but there will be a time in the future when God’s faithful ones will be gathered together and not one will be missing. “The covenant” referred to here is the New Covenant. We learn from other scriptures that when the people are judged (“passed under the staff”) the righteous will be separated from the unrighteous and the unrighteous will not enter into the Promised Land in Christ’s Millennial Kingdom but will be destroyed (Ezek. 20:38; 34:16). Jesus Christ speaks of this time of judgment as the Sheep and Goat Judgment (Matt 25:31-46).
[For more on the Sheep and Goat Judgment, see commentary on Matt. 25:32. For more on the Millennial Kingdom, Christ’s 1000 year kingdom on earth, see Appendix 3: “Christ’s Future Kingdom on Earth”].