כְּעַ֤ל גְּמֻלוֹת֙ כְּעַ֣ל יְשַׁלֵּ֔ם חֵמָ֣ה לְצָרָ֔יו גְּמ֖וּל לְאֹֽיְבָ֑יו לָאִיִּ֖ים גְּמ֥וּל יְשַׁלֵּֽם׃
他必按著他們所行的施行報應，照樣償還：烈怒歸給他的敵人，報應歸給他的仇敵；他也必向眾海島施行報應。
Rashi
According to their deeds As is fitting to recompense for what the enemies dealt to them.
Ibn Ezra
כעל גמלות Like a man who is zealous for repaying.19It is not clear from the words of I. E. whether this remark refers also to כעל ישלם, and explains it to mean like a man (who is zealous) for revenge, or is limited to כעל גמלות; in that case the whole phrase is to be translated, Like a man (who is zealous) for repaying, so he (is clad with zeal) for revenge. A. V., According to their deeds, accordingly he will repay. Fury to his adversaries, etc. He will repay fury to his adversaries, etc.