God extended the sacredness of life in this third prohibition by forbidding the eating of clean animals that had died without slaughter. He did so because the blood remained in them. The penalty for the offending Israelite was not as great because the life had departed from the animal. Nevertheless His people were to respect the symbol of life. [source][source][source]
"The faithful worshiper of the living God must preserve the sanctity of sacrificial blood, recognizing that life (signified by blood) belongs to God." [1][source]
In an interesting irony, Jesus taught that His blood gives eternal life and commanded His disciples to drink it (symbolically; cf. John 6:54). Jehovah"s Witnesses refuse to receive blood transfusions because of the commands about blood in this chapter. [2][source]
Chapter17 introduces the laws that follow in chapters18-26. Yet chapter17 is also important in the larger context of the Pentateuch. It presents the Israelite people committing idolatry with the goat idol as the Israelite priests had earlier committed idolatry with the calf idol ( Exodus 32). In the golden calf incident the priests led the people in idolatry, but here they opposed the idolatry of the people. The priests had evidently learned from their error and the legislation that God gave following that failure. Additional legislation designed to regulate the priests" behavior followed the priests" failure with the golden calf (i.e, the priestly code, Exodus 35 - Leviticus 16). Now additional legislation designed to regulate the people"s behavior followed the people"s failure with the goat idol (i.e, the holiness code, Leviticus 17:10 to Leviticus 25:55). [3][source]