John Gill's Bible Commentary Ver. 2. For thou art an holy people unto the Lord thy God , etc.] Set apart by him from all other people, and devoted to his worship and service, and many of them were sanctified and made holy in a special and spiritual sense; and therefore should not conform to the customs of Gentiles, whether in their extravagant mourning for the dead, or in their religious services; (see Deuteronomy 7:6), and the Lord hath chosen thee to be a peculiar people, above all the nations that [are] upon the earth ; to be his peculiar treasure, to be his peculiar servants and worshippers, to enjoy peculiar blessings and privileges, and behave in a peculiar manner different from all other people; and have no connection with them, especially in things sacred; and, in order to keep them a distinct peculiar people from all others, a peculiar diet was appointed them, that so being prohibited to eat such things as others did, they might be kept out of their company and conversation, and so from being drawn into their idolatrous practices; the rules concerning which follow; (see Deuteronomy 7:6).
Matthew Henry Commentary
Verses 1-21 - Moses tells the people of Israel how God had given them thre distinguishing privileges, which were their honour, and figures of those spiritual blessings in heavenly things, with which God has in Christ blessed us. Here is election; "The Lord hath chosen thee." He did not choose them because they were by their own acts a peculia people to him above other nations, but he chose them that they might be so by his grace; and thus were believers chosen, Eph 1:4. Here i adoption; "Ye are the children of the Lord your God;" not because God needed children, but because they were orphans, and needed a father Every spiritual Israelite is indeed a child of God, a partaker of his nature and favour. Here is sanctification; "Thou art a holy people. God's people are required to be holy, and if they are holy, they ar indebted to the grace God which makes them so. Those whom God choose to be his children, he will form to be a holy people, and zealous of good works. They must be careful to avoid every thing which migh disgrace their profession, in the sight of those who watch for their halting. Our heavenly Father forbids nothing but for our welfare. D thyself no harm; do not ruin thy health, thy reputation, thy domesti comforts, thy peace of mind. Especially do not murder thy soul. Do no be the vile slave
of thy appetites and passions. Do not render all around thee 
