The Scofield Bible Commentary, by Cyrus Ingerson Scofield, , at sacred-texts.com
Book Introduction - Joel
Joel, a prophet of Judah, probably exercised his ministry during the reign of Joash (2 Chronicles 22 to 24). In his youth he may have known Elijah, and he certainly was a contemporary of Elisha. The plagues of insects, which were the token of the divine chastening, give occasion for the unveiling of the coming "day of the Lord" (Isa 2:12, refs.), in its two aspects of judgment on the Gentiles and blessing for Israel.
Joel is in three chief parts:
1. The plague of insects (Joel 1:1-20)
2. The day of the Lord (Joel 2:1 - 3:8)
3. Retrospect of the day of the Lord, and full kingdom blessing (Joel 3:9-21)