zechor-na: the mitzvah to remember balak and bilam

The gemara (Brachos 12b) tells us that the Chachamim considered instituting a daily recitation of Parshas Balak along with kri'as shema. The gemara explains the significance of Parshas Balak based on the fact that it contains the pasuk "kara shachav k'ari" as well as an allusion to yetziyas Mitzrayim. However, the Pnei Yehoshua writes that there is more to it than that. The haftarah tells us "Zechor-na mah she'ya'atz Balak...u'meh ana bo Bilam...". From here we see that there is a mitzvah to remember the episode of Balak and Bilam. The Pnei Yehoshua writes that this remembrance must be done by verbally mentioning the parsha, hence the idea of instituting its reading along with shema.

Whether this chiddush of the Pnei Yehoshua is correct is debated by later achronim. Some note that though we do not read the entire Parshas Balak, we do hint to this episode by our recitation of the pasuk "Mah tovu..."

Why does the prophet Michah ask us to remember this parsha in particular? The explanation I once heard from R' Aharon Kahn is that unlike other episodes where the Jewish people knew that they faced grave danger and witnessed G-d's miraculous salvation, in this case the Jewish people would have not known at all that Bilam stood somewhere in the distance plotting their downfall until thwarted by Hashem. This parsha in particular teaches us that there is hashgacha operating behind the scenes saving us from dangers that we may not know about or anticipate.