What do we learn from "I will save you from all your Tum'os"?
Malbim: Even though there will still be a Yetzer ha'Ra, I will save you from all Tum'os.
Will Hashem call to the grain?
Radak: It is as if I call to it to increase ? I will send rain on it and guard it from Shidafon and Yerakon (parched by the east-wind, and dried and turned straw-yellow ? Rashi Devarim 28:22) and other mishaps.
Malbim: From the day that Taharah ceased, the [taste and] smell of Peros ceased (Sotah 48a). When you will be saved from your Tum'os I will call to grain 1 , and increase it with Hashgachah, lest there be hunger.
Malbim implies that calling to it means that the [taste and] smell of Peros will return, and also, He will increase it. (PF)