'Sign' in the Bible

You shall bind them for a sign on your hand, and they shall be for symbols between your eyes.

Therefore you shall lay up these my words in your heart and in your soul; and you shall bind them for a sign on your hand, and they shall be for symbols between your eyes.

If there arise in the midst of you a prophet, or a dreamer of dreams, and he give you a sign or a wonder,

and the sign or the wonder come to pass, of which he spoke to you, saying, "Let us go after other gods" (which you have not known) "and let us serve them;"

and they shall be on you for a sign and for a wonder, and on your seed forever.