'Guard' in the Bible

“Only be on your guard and diligently watch yourselves, so that you don’t forget the things your eyes have seen and so that they don’t slip from your mind as long as you live. Teach them to your children and your grandchildren.

Be on guard so that you do not forget the covenant of the Lord your God that he has made with you, and that you do not make an image of any kind, just as he has forbidden you.

If you build a new house, you must construct a guard rail around your roof to avoid being culpable in the event someone should fall from it.

"When you are encamped for battle against your enemies, be on guard against every form of impropriety.