In Eikev, Moshe reminds B’nei Yisrael that Hashem provided manna in the wilderness “so that He would make you know that man does not live by bread alone, but rather by, whatever comes forth from the mouth of Hashem does man live.”
Moshe also speaks of the goodness of Eretz Yisrael, a land with “wheat and barley, vines and figs and pomegranates, a land of oil producing olives and (date) honey,” (the seven species) “a land in which you will eat bread without scarcity.”
And then follows the pasuk that is the source for the obligation to say Birkat HaMazon: “And you will eat and be sated, and you shall bless Hashem, your G-d, for the good land He has given you.” (also here and here)
This week’s parsha project was making challah. We made a batch of whole wheat and a batch of regular challah. The whole wheat challah included some silan (date honey) and olive oil. The white flour used for making the regular challah includes some barley flour. Part of the dough was used to make a cinnamon raisin pull apart loaf. So, our challah included five of the seven species: barley, grapes, olives, dates, wheat.
For one of the challahs, I made a four-strand with two white and two whole wheat strands: