Smith's Bible Dictionary (1863)
the Greek form of the ancient word has-Shefelah, the native name for the southern division of the low-lying flat district which intervenes between the central highlands of the holy land and the Mediterranean, the other and northern portion of which was known as Sharon. The name occurs throughout the topographical records of Joshua. The historical works, and the topographical passages in the prophets always with the article prefixed, and always denoting the same region. ” The Shefelah was and is one of the most productive regions of the holy land.
It was in ancient times the cornfield of Syria, and as such the constant subject of warfare between Philistines and Israelites, and the refuge of the latter when the harvests in the central country were ruined by drought.