This verse limits the application of the symbol. Only the ungodly and the idolatrous part of the people decayed at Babylon. The religious portion was strengthened and invigorated by the exile Jeremiah 24:5-7.
Related Commentaries of Jeremiah 13:10
Jeremiah 13:10
10 This evil people, which refuse to hear my words, which walk in the imaginationa of their heart, and walk after other gods, to serve them, and to worship them, shall even be as this girdle, which is good for nothing.