'Guard' in the Bible

Therefore, Lord God of Israel,keep what You promisedto Your servant, my father David:You will never fail to have a manto sit before Me on the throne of Israel,if only your sons guard their walk before Meas you have walked before Me.

As the king was passing by, he cried out to the king and said, “Your servant marched out into the middle of the battle. Suddenly, a man turned aside and brought someone to me and said, ‘Guard this man! If he is ever missing, it will be your life in place of his life, or you will weigh out 75 pounds of silver.’