'Sign to You' in the Bible

He answered, “I will certainly be with you, and this will be the sign to you that I have sent you: when you bring the people out of Egypt, you will all worship God at this mountain.”

Isaiah said, “This is the sign to you from the Lord that He will do what He has promised: Should the shadow go ahead 10 steps or go back 10 steps?”

This is the sign to you from the Lord that He will do what He has promised:

This will be a sign to you’—this is the Lord’s declaration—‘that I am about to punish you in this place, so you may know that My words of disaster concerning you will certainly come to pass.