Genesis 17:11

11You shall be circumcised in the flesh of your foreskins, and it shall be a asign of the covenant between me and you.

Exodus 12:13

13 bThe blood shall be a sign for you, on the houses where you are. And when I see the blood, I will pass over you, and no plague will befall you to destroy you, when I strike the land of Egypt.

Ezekiel 20:12

12Moreover, I gave them cmy Sabbaths, as a sign between me and them, dthat they might know that I am the Lord who sanctifies them.
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