לוּלֵי֙ יְהוָ֣ה צְבָא֔וֹת הוֹתִ֥יר לָ֛נוּ שָׂרִ֖יד כִּמְעָ֑ט כִּסְדֹ֣ם הָיִ֔ינוּ לַעֲמֹרָ֖ה דָּמִֽינוּ׃ (ס)
Except the LORD of hosts Had left unto us a very small remnant, We should have been as Sodom, We should have been like unto Gomorrah.
Read Jewish philosophy on Isaiah 1:9: Rambam's Guide for the Perplexed, Saadia Gaon, and classical Jewish philosophical sources, free online.