The Desert in Words: G-d's Committment to the Land, and the Torah Portion of Eikev

One of the main themes of this week's Torah portion is primarily about reward for following G-d's commandments. Last week's sixth Aliyah (reading) contained the first paragraph of the Shemah, and this week's portion contains the Shemah's second paragraph. It also contains a somewhat puzzling comment by Rashi.
 
The sixth aliyah has a few additional verses before reaching the part contained in the Shemah:
 
10. For the land to which you are coming to possess is not like the land of Egypt, out of which you came, where you sowed your seed and which you watered by foot, like a vegetable garden.
11. But the land, to which you pass to possess, is a land of mountains and valleys and absorbs water from the rains of heaven,

12. a land the Lord, your God, looks after; the eyes of Lord your God are always upon it, from the beginning of the year to the end of the year.

13. And it will be, if you hearken to My commandments that I command you this day to love the Lord, your God, and to serve Him with all your heart and with all your soul...
 
Rashi - And it will be, if you hearken: וְהָיָה (Vehayah) is referring to what is said above (verse 11):“and absorbs water from the rains of heaven”
 
Why does Rashi feel that it is necessary to note that Vehayah is referring back to verse 11 (describing rain) and not a continuation of the previous verse, about how Hashem's eyes are always upon the Land "from the beginning of the year to the end of the year?"

The answer, perhaps, is a simple one. As mentioned previously, much of this Torah portion is about a certain quid pro quo, reward and punishment. Rashi's comment serves to emphasize that G-d's eyes will always upon the Land. Unlike the rain, harvests, etc., this is not subject to change. G-d will always look after the Land in a very special way, no matter what.