The mekubal Rav Tzvi Hirsch Koidenover wrote in his sefer Kav Hayashar (Ch. 96) about the tremendous shefa a person who is strict about amen merits, and chalilah the converse: “Because anyone who answers amen with kavanah and hurries to the beis knesses to answer amen – merits the 370 nehorin by answering amen. And anyone who shames amen, and answering amen is light in his eyes – then his soul is preceded by 370 klipos, R”l. And he is taken to dark deathly rooms, and of them the Navi said (Yeshayah 50:9): “עש יאכלם.”
The Kav Hayashar goes on to explain that those 370 nehorin illuminated for Esther Hamalka, and as an allusion to that great light, we light a lot of candles on Purim to illuminate the shuls with the same precious light, and of this it is said (Esther 8:16): “LaYehudim haysah orah vesimchah...”
