Ephraim feedeth on wind, and followeth after the east wind. "Wind" is employed figuratively to denote what is empty and vain, of no real worth or practical benefit.
1. To feed on wind is to take pleasure in or draw sustenance from what can really afford neither; while following after the east wind is
2. The Septuagint rendering is ὁ δὲ ἐφραὶμ πονηρὸν πνεῦμα ἐδίωξε καυδώνα, equivalent to "But Ephraim is an evil spirit; he has chased the east wind." He daily (rather, all the day) increaseth lies and desolation. Some understood these words