When did Elisha tell her to go?
Malbim: It was before the seven years of hunger. The subject precedes the verb, to teach that this is a past participle (it happened before the previous matter). 1
Also, it says "Diber", and not va'Ydaber; refer to Bereishis 4:1:1:1. (PF)
Why does it mention that he revived her son?
Malbim: Elisha had the power to cancel the decree of hunger, but since he revived the boy and took the Mafte'ach (key) of Techiyas ha'Mesim, he could not take the Mafte'ach of income. This is like Chachamim said that for this reason, when Eliyahu needed to revive the widow's son, he needed to return the Mafte'ach of rain 1 .
After he revived him, he could have returned the Mafte'ach of Techiyah, and asked for the Mafte'ach of income! (PF)
Why is there a Yud at the end of "At"?
Radak: It is extra. We find this often, like I wrote (refer to 4:23:1:1).
What is the meaning of "Kara Hashem la'Ra'av"?
Malbim: Hashem already decreed it, and it already began - "v'Gam Ba El ha'Aretz."
"La'Ra'av" with a Patach under the Lamed is in place of Hei ha'Yedi'ah (to identify), i.e. it is a known hunger!
Rashi: It is the famine that was in the days of Yo'el.
What did they eat during the seven years?
Radak (citing Ta'anis 5a): The first year, they ate what was in the houses. The next six years, they ate, respectively, what was in the fields; Tahor animals; Tamei animals; vermin; their sons and daughters; and their arms, to fulfill "Ish Besar Zero'o Yochelu" (Yeshayah 9:19).
