申命记 32:41

אם שנותי ברק חרבי means, IF I SHALL WHET THE BLADE OF MY SWORD, so that it shall have a flash (ברק); splendeur in old French ותאחז במשפט ידי AND MY HAND TAKE HOLD ON JUDGMENT — i.e., on strict justice, relinquishing (i.e. withdrawing) My attribute of mercy from My enemies who have done so much evil unto you, — “I was angry only a little, but they helped to do harm” (Zechariah 1:15). — but My hand shall grasp the attribute of justice to hold fast to it in order to take vengeance. אשיב נקם וגו׳ I WILL RENDER VENGEANCE [TO MY ADVERSARIES]. — Our Rabbis derived in the Agada from the wording of the text which states, “And My hand shall hold the משפט fast”, that the nature of the Holy One, blessed be He, is not like the nature of human beings: The nature of a human being is that when he shoots an arrow he cannot bring it back (i.e., cannot check its flight); the Holy One, blessed be He, however, shoots His arrows and it is in His power to bring them back as though He is still holding them in hand, for, you see, lightning is His arrow, for it states here ברק חרבי, “Lightning is my weapon, and my hand holds fast to משפט" (Mekhilta). This משפט (i.e., משפט according to this explanation) has the meaning of punishment, in old French justicia, the execution of justice (the third definition given by Rashi on Exodus 28:15 of this word)

אִם־שַׁנּוֹתִי֙ בְּרַ֣ק חַרְבִּ֔י        וְתֹאחֵ֥ז בְּמִשְׁפָּ֖ט יָדִ֑י אָשִׁ֤יב נָקָם֙ לְצָרָ֔י        וְלִמְשַׂנְאַ֖י אֲשַׁלֵּֽם׃

If I whet my glittering sword, and my hand take hold on judgment; I will render vengeance to my enemies, and will reward those who hate me.