When did Yo'el live?
Rashi citing Bamidbar Rabah 11: Puti'el means, he was the son of Shmuel ha'Navi, who was Mefateh (enticed) Hashem with his prayer.
Rashi: Some say 1 that his Nevu'ah of seven years of famine were the years that Elisha predicted "Ki Kara Hashem la'Ra'av..." (Melachim II, 8:1). They were in the days of Yehoram ben Achav. Radak - there were four years of four kinds of locusts, and rain was withheld for three years.
Rashi citing Bahag, Seder Olam 20: Yo'el, Nachum and Chabakuk were in the days of Menasheh. Radak - because Menasheh was improper, it does not say that it was in his days.
Ta'anis 5a implies so; it is not explicit. (PF)
What is the content of this Sefer?
Radak: First he prophesizes about the locusts that Hashem will bring in Eretz Yisrael due to their sins. Afterwards is a Nevu'ah for the days of Mashi'ach.
