Jeremiah 2:3

Israel was holiness unto the Lord
When first brought out of Egypt into the wilderness, by the Lord's choice and separation of them to be a holy people to him above all others; by covenant with him, and profession of him; and by his giving them holy laws, and placing a sanctuary among them; and by their high priest, who represented them in the most holy place; and had on the front of his mitre written, holiness unto the Lord;
so the spiritual Israel are chosen in Christ to be holy, and he is made sanctification to them; they are sanctified in him, and by his Spirit; they are called with a holy calling, and unto holiness; and, under the influence of grace, live holy lives and conversations, which the grace of God teaches, and young converts are remarkable for; their consciences being just awakened, and their hearts tender: and the firstfruits of his increase;
Israel was the first nation that God separated for himself; and this being the firstfruits, shows that he would separate others also, and take out of the Gentiles a people for his name, which he has since done; and the elect of God among the Israelites were the firstfruits of his chosen ones elsewhere; it were some of them that first believed in Christ, and received the firstfruits of the Spirit; and all converted ones are a kind of firstfruits of his creatures; the grace they receive at conversion is the firstfruits of a later increase of it, and even of eternal glory: all that devour him shall offend;
or, "all that eat him shall be guilty" ^F24; and be condemned and punished, who eat up the Lord's people, as they eat bread; see ( Psalms 53:4 ) , these shall not go unpunished; for his people are as the apple of his eye, and whoever touches and hurts them fall under the divine displeasure, and will be looked upon as criminals and offenders, and will be judged and condemned as such. The allusion is to the eating of the firstfruits, which only belonged to the priests; nor might any of the increase be eaten until the firstfruits were brought to them, ( Leviticus 23:10 Leviticus 23:14 Leviticus 23:20 ) . This is expressed in the Chaldee paraphrase of the text,

``whosoever eats of them (the firstfruits) is guilty of death; for as the beginning of the harvest, the sheaf of oblation, whoever eats of it before the priests, the sons of Aaron, have offered of it upon the altar, shall be guilty or condemned; so all that spoil the house of Israel shall be guilty or condemned;''