Adam Clarke on Exodus 29:20

Take of his blood - The putting the blood of the sacrifice on the tip of the right ear, the thumb of the right hand, and the great toe of the right foot, was doubtless intended to signify that they should dedicate all their faculties and powers to the service of God; their ears to the hearing and study of his law, their hands to diligence in the sacred ministry and to all acts of obedience, and their feet to walking in the way of God's precepts. And this sprinkling appears to have been used to teach them that they could neither hear, work, nor walk profitably, uprightly, and well-pleasing in the sight of God, without this application of the blood of the sacrifice. And as the blood of rams, bulls, and goats, could never take away sin, does not this prove to us that something infinitely better is shadowed out, and that we can do nothing holy and pure in the sight of a just and holy God, but through the blood of atonement? See Clarke's note on Exo 30:20.