John Trapp on Esther 9:23

Verſe 23. And the Jewes undertook to do as they had begun] Which yet they could not do, unleſſe God gave them an heart to do it. Holy David underſtood this, and therefore when he found that heat and height of good affections in his people, he prayed, O Lord God of Abraham, Iſaac, and of Iſrael our fathers, keep this for ever in the imagination of the thoughts of the heart of thy people, and ſtabliſh their heart unto thee, 1 Chron. 29.18. And when he had at another time undertook for himſelf, that if God would deliver him from blood-guiltineſſe, his tongue ſhould ſing aloud of Gods righteouſneſſe, he ſubjoynes (by way of correction, as if he were ſenſible that he had promiſed more then was in his power to perform) O Lord, open thou my lips, and my mouth ſhall ſhew forth thy praiſe, Pſal. 51.14, 15. The Hebrew, or rather Chaldee word here rendred Ʋndertook, is of the ſingular number, to ſhew, that every particular Jew undertook for himſelf, and for his poſterity to all perpetuity. And indeed they keep this feaſt annually to this day, and exceedingly pleaſe themſelves in the reading of this hiſtory, counting and calling all ſuch Princes and States as croſſe them, Hamans, and wiſhing that they may be able one day to be avenged of them, as their fathers were of theſe Perſians, &c.