Of the flesh, i.e. of living creatures. Is in the blood, i.e. it depends upon the blood, is preserved and nourished by it, and is extinguished when the blood is gone. And this law was given to the Jews, and hard-hearted people, as they are oft said to be, that by this restraint from the blood of brute creatures they might be wrought to the greater abhorrency of taking away the life of a man. It is the blood that maketh an atonement; typically, and in respect of the blood of Christ, which it represented, by which the atonement is really made, Hebrews 9:12. So the reason is double:
1. Because this was the eating up of the price or ransom of their own lives, which in construction was the destroying of themselves.
2. Because this was ingratitude and irreverence towards that sacred blood of Christ which they ought to have in continual veneration.