Exodus 8:19

8:19 The magicians said to Pharaoh, “It is the finger of God!” But Pharaoh’s heart remained hard, and he did not listen to them, just as the Lord had predicted.

Exodus 29:12

29:12 and take some of the blood of the bull and put it on the horns of the altar with your finger; all the rest of the blood you are to pour out at the base of the altar.