'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,

“But you, be on your guard! They will hand you over to sanhedrins, and you will be flogged in the synagogues. You will stand before governors and kings because of Me, as a witness to them.

But be on your guard; I have told you everything in advance.

“Be on guard and stay constantly alert [and pray]; for you do not know when the appointed time will come.