'Be on Your Guard' in the Bible

and when He admonished them, "See to it, be on your guard against the yeast of the Pharisees and the yeast of Herod,"

Moreover in the course of His teaching He said, "Be on your guard against the Scribes who like to walk about in long robes and to be bowed to in places of public resort,

"You yourselves must be on your guard. They will deliver you up to Sanhedrins; you will be brought into synagogues and cruelly beaten; and you will stand before governors and kings for my sake, to be witnesses to them for me.

But as for yourselves, be on your guard: I have forewarned you of everything.