Men, base fellows, have gone out from your midst and have led astray the inhabitants of their city, saying, “Let us go and serve other gods” that you have not known.
English: “And they have led astray” — and not that they strayed of their own accord.
On the daf / in context: If the inhabitants adopted idolatry spontaneously without external seducers, the city is not judged as an ir ha-nidachas; each person is treated as an ordinary individual idolater.
Type of Learning
Derash on the verse (Sanhedrin) — spontaneous adoption of idolatry does not create ir-ha-nidachas status.
What Is Learned
An ir ha-nidachas requires active seduction by others; if the people strayed on their own they are judged as individuals.