Exodus 4:9

4:9 And if they do not believe even these two signs or listen to you, then take some water from the Nile and pour it out on the dry ground. The water you take out of the Nile will become blood on the dry ground.”

Exodus 12:22

12:22 Take a branch of hyssop, dip it in the blood that is in the basin, and apply to the top of the doorframe and the two side posts some of the blood that is in the basin. Not one of you is to go out the door of his house until morning.

Exodus 29:20

29:20 and you are to kill the ram and take some of its blood and put it on the tip of the right ear of Aaron, on the tip of the right ear of his sons, on the thumb of their right hand, and on the big toe of their right foot, and then splash the blood all around on the altar.

Exodus 30:10

30:10 Aaron is to make atonement on its horns once in the year with some of the blood of the sin offering for atonement; once in the year he is to make atonement on it throughout your generations. It is most holy to the Lord.”