I am the LORD your God: See study note on Leviticus 18:2.
be holy, because I am holy: These words express the main theme of Leviticus: God is holy. They must consider and treat God as holy. God expects holiness from his people (Leviticus 10:3; 19:2). This verse teaches that God's character influences those who make a covenant with him (see also 11:45; 20:7, 26; 21:8, 15; 22:9, 16, 32). They must become holy in their actions (Exodus 22:31; Deuteronomy 28:9; compare 1 Peter 1:16).