ישעיהו מט:ב פירוש: רש״י ואבן עזרא

And He made my mouth like a sharp sword to castigate the wicked and to prophesy retribution upon them.

And He hath made my mouth like a sharp sword, to speak elegantly; or, as was the case in his prophecies against Babylon, to speak sharply; and the meaning of the whole phrase is accordingly : Although God has made my mouth like a sharp sword against the Babylonians, neither the Babylonians nor the wicked men in Israel, could do any harm to me,

He concealed me in the shadow of His hand that they be unable to harm me.