Mattos
Mattos is a parsha of vow and their annulment.
It begins with the rules of vows: Al taacher, do not delay, goes on to the the annulment of women's vows, and ends with the vows of Reuben and Gad, vows that are given in exchange for a tract of land.
Behind all of this there is an implicit vow. That is the promise of G d to bring the people into the holy land. The fulmillment of that vow ( actually that set of vows to the Patriacrchs) is quite delayed. The accompanying parsha of Massei begins with the details of that delay, the set of journeys that the Bnei Yisroel take thorugh the wilderness on the way to the land promised to them by the Enforcer of All Vows. The vow is invalidated by our misunderstanding.