Lo tishma el divrei hanavi ha'hu....
Acharei Hashem Elokeichem teilechu v'oso tira'u, v'es mitzvosov tishmoru v'oso ta'avodu u'bo tidbakun
V'hanavi ha'hu... yumas... (13:4-6)
Why does the Torah stick the long exhortation to follow Hashem, observe mitzvos, emulate Hashem's midos, etc. in the middle of the parsha, in between telling is not to listen to the navi sheker and the navi sheker's punishment? Why not complete the topic of navi sheker and then come back to what we should be doing instead of listening to false prophets?
The navi sheker is bound to cause confusion, to damage people's committment, to have a negative effect on the community. One might think that there could not be a worse time to start a new Torah endeavor than in the middle of dealing with such a terrible situation. Let the tzarah pass and then we can get to other things!
The Torah here is telling us not to wait. Even in the midst of calamity, one can spark a new positive beginning.