In Nehemiah, chapter thirteen, verse three, the exclusion of pagan foreigners from Israel was to erect a barrier between God’s people and the wicked practices of unbelievers. The understanding of why God desired this is in the inherent tendency of His people to conform to the ways, pleasures, and lifestyles of the world. An essential requirement for God’s people who would be holy is to remain separate from the ways, values, and ungodly customs of our society and to stand against the prevailing and popular expressions of the spirit of this world. The failure to do so will result in the loss of God’s presence and all the good He has determined for us.
All the Ammonites, Moabites, and other heathenish people with whom they had contracted alliances. All these were out from the congregation of Israel, together with the children born of them; that is, they would not look upon them as Israelites or as entitled to the same privileges as themselves. Israel is known as a peculiar people and was not supposed to mingle with the nations.
See the benefit of publicly reading the word of God when believers address it properly: they will discover sin and duty, good and evil, and shows wherein they have erred. The people of God profit when they are wrought upon to separate from evil. Those that would drive sin out of their hearts, the living temples, must throw out their household stuff and all the provision made for it and take away all the things that are the food and fuel of lust; this is really to mortify it. When sin is cast out of the heart by repentance, let the blood of Christ be applied to it by faith, then let it furnish with the graces of God’s Spirit for every good work.