Matot and Mas'ei are one of seven pairs of sedras that are sometimes combined and sometimes read separately.
They are the most often combined of those seven pairs. Outside of Israel, they are read separately only a bit more than 10% of the time. In Israel, because of the out-of-sync catching up, they are separated another 10% of the time. Still, they are the most-often combined pair.
An interesting gimatriya points to their combinedness - the first pasuk of each have the same numeric value.
Furthermore, Matot and Mas'ei are always read during the Three Weeks, whether combined or separated.
All that said, the sedras highlight the fact that B'CHOL DOR VADOR... in every generation, we, the Jewish People, and we as individual Jews, find ourselves reminded of two very different directions that our ancestors chose between AND that we today are still challenged to chose.
When the tribes of Reuven and Gad asked permission not to cross the Jordan, but rather to settle on the eastern side of the river, Moshe saw that as 'here we go again', the Meraglim are alive and well almost 40 years after the devastating decree against the adult male population of the generation who came our of Egypt.
However it worked out, it really shook Moshe Rabeinu up. And it should still give us pause to ponder.
And the travelog at the beginning of Mas'ei should also remind us of the results of the panic induced by the spies who spoken negatively of fulfilling G-d's will for us to live in Eretz Yisrael. An 11-day trip took us 40 years. That's bad enough. A major portion of the population didn't make it.
And then Mas'ei presents us with another chance. Not for Dor HaMidbar, but for every Jew in all succeeding generations. Including today.
Here is Ramban's Mitzva #4 - To dwell in the Land of Israel. Not to allow it to fall into 'other' hands. Not to choose anywhere else in the world as our real home.
As we've said before (more than once), we are not judging the Generation of the Wilderness. We cannot know what it was like to here 10 tribal leaders warn us of the dangers if we were to try to conquer the Land and to here two others talk about doing G-d's will and not being afraid, and not doubting Him or ourselves.
But we are at the same crossroads. Do we perpetuate the sin of the spies, to we perpetuate Tish'a b'Av - or - do we commit ourselves to living in Eretz Yisrael al pi Torat Yisrael?