What is the meaning of "Goren va'Yekev Lo Yir'em"?
Radak: Since they do not recognize that I give to them grain and wine, and they abandon My Avodah and serve other gods, the granary and winepress will not feed them, for I will bring against them Shidafon and Yerakon (parched by the east-wind, and dried and turned straw-yellow ? Rashi Devarim 28:22), locusts or the enemy. They will not make a granary or winepress. This is like it says above, "she did not know that I gave to her grain, wine and oil" (2:10).
Malbim: This refers to the food that her Husband stipulated to give to her at the time of Nisu'in. They will not find their food in their land's granary.
How will wine deny?
Radak: Before it mentioned Goren va'Yekev. Goren is in order to make bread; Yekev has two benefits ? grapes for eating, and wine. What they hoped to get, they will not find, for Hashem's curse will be in it "Ba El ha'Yekev Lachsof Chamishim Purah v'Haysah Esrim" (Chagai 2:16).
Malbim: They will not find grain and wine there, like they used to. Malbim (3) - their wine used to blessed in the merit of those who dwell in Eretz Yisrael, and due to Nechasim. Now, they will not dwell in their land (3), and they will not offer Nechasim (4)!
Why does it say "Bah?
Radak: This refers to Adas Efrayim. Sometimes the singular is used for the Klal, and sometimes the plural for the individuals, and sometimes feminine [singular] for the Edah.
Radak citing Mesorah: This is one of the two places in which it is written Bah, and we explain Bam. The other is "va'Yaku Vah" (Melachim II, 3:24).