'Act' in the Bible

Then God said, "Let there be lights across the sky to distinguish day from night, to act as signs for seasons, days, and years,

Just then Jacob's sons arrived from the field. When they heard what had happened, they were distraught with grief and livid with anger toward Shechem, because he had committed a disgraceful deed in Israel by forcing Jacob's daughter to have sex, an act that never should have happened.

"Your Excellency," they replied, "Why do you speak like this? Far be it from your servants to act like this.