Jamieson, Fausset and Brown on Leviticus 17:13-14

13-14. whatsoever man ... hunteth--It was customary with heathen sportsmen, when they killed any game or venison, to pour out the blood as a libation to the god of the chase. The Israelites, on the contrary, were enjoined, instead of leaving it exposed, to cover it with dust and, by this means, were effectually debarred from all the superstitious uses to which the heathen applied it.