Calvin's Commentaries, Vol. 28: Jonah, Micah, Nahum, tr. by John King, [1847-50], at sacred-texts.com
At what time Jonah discharged the office of a Teacher, we may in some measure learn from 2Ki 14:1 for it is certain that he is the person there mentioned in Sacred history, as he is expressly called the son of Amittai 8 . It is said there that Jeroboam, the son of Joash, had enlarged the borders of his kingdom, from the entrance into Hamath to the sea of the desert, according to the word of Jonah, the servant of God, the son of Amittai, who came from Gath. It was then at that time, or shortly before, that Jonah prophesied. And it is certain that he was not only sent to the Ninevites, but that he also was counted a Teacher among the people of Israel. And the beginning also of his Book seems to intimate what I have said, — that he was an ordinary Prophet among the people of Israel, for it begins with a copulative, And the Word of the Lord came to Jonah. Though the Holy Spirit does in other places speak sometimes in this manner, yet I doubt not but that Jonah intimates that he was recalled from the discharge of his ordinary office, a
nd had a new charge committed to him, — to denounce, as we shall see, on the Ninevites a near destruction.
We must now then understand, that Jonah taught among the people of Israel, but that he received a command to go to the Ninevites. Of this command we shall take notice in its proper place; but it is right that we should know that he was not then only made a Prophet, when he was given as a Teacher to the Ninevites, but that he was sent to the Ninevites after having for some time employed his labors for God and his Church.
This Book is partly historical and partly didactic. For Jonah relates what happened to him after he had attempted to avoid the call of God, and what was the issue of his prophecy: this is one thing. But at the same time he mentions the kind of doctrine which he was commanded to proclaim, and he also writes a Song of Thanksgiving. This last part contains doctrines and is not a mere narrative.
He was of Gath-hepher, in the tribe of Zebulun, a part of lower Galilee, Jos 19:13. He prophesied in the reign of Jeroboam the second, king of Israel, who began to reign 823 before Christ, and reigned in Samaria 41 years. See 2Ki 14:23-25.” — Newcome.