John Trapp on Joel 2:18

Verſe 18. Then will the Lord be jealous (or, Zealous) for his land] Then dicto citiùs ſtraight upon't; no ſooner ſhall you repent (as is preſcribed,) but the Lord will be jealous &c. Of Gods jealouſie for his people, ſee the Note on Zech. 1.14. and 8, 2. And of the happy effect of faſting turned to feaſting, ſee the Note on Zach. 8.19. See alſo Judg. 20.23. Ezra. 9.6. Dan. 9.20. 2 Chron. 20. Bacah turned into Berachah: beſides the conſtant experience of theſe and former times, of the happy ſucceſſe and unmiſcarrying returns of holy faſting and prayer: no inſtance to the contrary. God uſually anſwers his humbling people, as here, according to the deſire of their hearts: neither ſo only, but according to the requeſt of their lips alſo.Aug. Confeſſ. l. 5. c. 8. Pſal. 21.2. he fits his mercy ad cardinem deſiderii: and lets it be to his, even as they will. They ſay Spare thy people, and accordingly he will pitty or ſpare his people, ſaith the Prophet. They would not have God to give his heritage to reproach by inflicting famine upon them, as if they ſerved an hard maſter that would affamiſh them. To this God gives a full anſwer in the next verſe, Behold I will ſend you corn &c. Again, they deſire God to take care of his own great name, and to vindicate it. I will, ſaith God, by doing greateſt things for you Verſe. 20. and by cauſing the blaſphemers to return and diſcern that their Rock is not as your Rock, themſelves being judges: and that to ask, where is now their God? Deut. 32. is as great folly, as if one ſhould ſay, betwixt the ſpace of the new and old moon, Where is now the Moon? when as it is never neerer the Sun, then at that time. There are ſome Interpreters of good note, that read this verſe not in the Future, but in the Preter tenſe, thus, Then was the Lord zealous for his land, and pittied his people, Mercer. Leveleus. ſc. when once he ſaw them ſeriouſly to repent, he did all this that followeth for them. Neither maketh it any thing againſt this interpretation, that the repentance of this people, their aſſembling and faſting &c. is not recorded. For no more is it that Moſes went to Pharaoh according to Gods command, to threaten thoſe ſwarmes of flies Exod. 8.20. or that Eſay took his ſon Shear-iaſhub, and went to Ahaz to confirme and comfort him, as God had commanded Eſay. 7. which yet we doubt not but the Prophet did. This is an ordinary Apoſiopeſis.

and pitty his people] Or, ſpare them, pardon them. The word ſignifies to ſhew mercy to him whom by all right thou mayeſt juſtly deſtroy Ezek. 5.11. 1 Sam. 15.3. Oh the divine Rhetorick, and omnipotent efficacy of Repentance! This is the rainbow, which if God ſeeth ſhining in our hearts, he will never drown our ſoules.Fulgent. Dat poenitentiam & poſte à indulgentiam, He gives his people to repent, and then ſpareth them as a man ſpareth his own ſon that ſerveth him. But it is otherwiſe with thoſe that partake not of the divine nature:Mal. 3.17. they are fierce, and implacable, as is the devill, who workes effectually in them, as a ſmith doth in his forge. Henry the fourth Emperour of Germany came in the middeſt of a ſore winter upon his bare feet, to the gates of the caſtle of Canuſium, and ſtood there faſting from morning to night for three dayes together, waiting for the judiciall ſentence of the Pope, and craving pardon of him; which yet he could not obtaine by his own or others tears, or by the interceſſion of any Saint, ſave only of a certain harlot, with whom the Pope was then taking his filthy pleaſure. The Emperour miſtooke, who thought that the Pope could be pacified by faſting and prayer. This God required another kind of ſacrifice, then theſe.