Amos was not a professional prophet or a disciple in training. He had no financial reason to leave his job to prophesy.
herdsman: The Hebrew word here differs from the one in Amos 1:1 and is not found elsewhere in the Old Testament. It relates to a word for cattle, suggesting Amos may have raised cattle as a breeder or herder (see Amos Book Introduction, “The Prophet Amos”).
The sycamore-fig was gathered for cattle feed.