"For you are a holy people to the LORD your God, and the LORD has chosen you to be a people for Himself, a special treasure above all the peoples who are on the face of the earth." (v.2)
The idea here in our text behind Israel's identity as "a holy people" is that they were "separate" unto the LORD, chosen by God, to be His own special people. In Jesus, we too are a chosen people, special to God: as Peter wrote, "But you are a chosen generation… His own special people (1 Peter 2:9).
We also see in out text that Israel was, a special treasure to God. Each of these glorious privileges carried with it a special responsibility. If God regarded Israel as something special among the nations, then they had to conduct themselves as something special, different from all the peoples on the face of the earth.
Therefore, beginning in v.3, we see God's command to His people to separate themselves form other people and nations in regard to foods. Moses then goes on to reiterate these dietary laws for the people of Israel in vv.3-21 in regards to which meats were considered clean and which were unclean. These laws, given to Moses by God, severed the people well not only in Moses’ day, but for centuries to come. During the Middle Ages when plagues and disease devastated the continent of Europe, the Jewish people were singularly protected from many of them because of their adherence to the dietary laws found here in the book of Deuteronomy.
These dietary laws may seem strange to us but, they were medically correct and profoundly healthy for that time period. Jesus later used this idea of diet to speak metaphorically of spiritual defilement saying, “It’s not what goes into your body that defiles you; you are defiled by what comes from your heart.” (Mark 7:15) With this in mind, we as Christians today need to be on guard against what goes into our hearts that is unclean, rather than what goes into our bodies.
How do we do that? The eyes are the gateway to our minds and to our souls. Therefore, we need to filter what we see through the spiritual lens of, "clean vs unclean" - as spiritual defilement has serious consequences. Therefore, “Be careful little eyes what you see.”
The Truth: “If anyone defiles the temple of God, God will destroy him. For the temple of God is holy, which temple you are.” (1 Corinthians 3:17)
