Jeremiah 17:17

Now the Prophet, having appealed to God as a witness to his integrity, prays him to show himself as his patron and defender. Thus he again implores God’s aid, Be not thou, he says, a terror to me, that is, “Suffer me not while pleading thy cause to be terrified.” Thy the word, terror, he means such a dread as stupifies all the feelings. It would have indeed been wholly unreasonable for the Prophets to fail in constancy and firmness, for it belonged to God to rule them by his Spirit, and to support them by his grace, from the time he committed to them their office. Since then no one is of himself fit to discharge the duties of a faithful teacher, God must: necessarily succor and aid those whom he calls and sends to the work. This is now what the Prophet speaks of when he says, Be not to me a terror, that is, “Be not to me a cause of dread by depriving me of constancy and firmness, so as to render me an object of ridicule to all;” and why? because thou art my protection, or my hope, for the word means both.

Thou art then my protection (of this meaning I mostly approve) in the day of evil, that is, “I have chosen thee as my protector, as though thou were a shield to me; as then I have promised myself the favor of having thee as my help, see that I be not left destitute, since I have to right for thee and under thy banner.” Hence he adds, Ashamed let them be who persecute me, and let not me be ashamed; terrified let them be, and let not me be terrified