But be sure you do not eat the blood, because the blood is the life, and you must not eat the life with the meat. Deuteronomy 12:23
God values life. He should because every living thing on this earth comes from his hand. What is the mark of life? For plants it is their roots; for us it is our blood. To honor life, God decreed that people could not touch blood, for once blood is outside of the vascular system—it is a sign of death, not life. So God called for them to drain the blood of the animals butchered to be eaten before they ate it. God chose blood to remind us of the value of life; he chose for Jesus to spill his blood that you might see how far he would go to save your life—his own death. Have a good day.