'Guard' in the Bible

And you must set limits [for] the people all around, saying, 'Guard yourselves {against} going up to the mountain and touching its edge. Anyone touching the mountain will certainly be put to death.

And ye shall be on your guard as to everything that I have said unto you; and shall make no mention of the name of other gods it shall not be heard in thy mouth.

"Look, I'm sending an angel in front of you to guard you on the way and to bring you to the place I've prepared.

Be on your guard before him and obey his voice; do not be rebellious toward him, for he will not pardon your transgression, since My name is in him.