Perceptible movements of air masses. Winds were an important determinant of weather in ancient Palestine. In the rainless summer months moisture-laden winds from the Mediterranean (west or northwest) flowed over the land during the daytime, moderating the midday heat and leaving a heavy dew at night. In the winter months the western winds brought thunderstorms (1Kgs 18:45). Unstable weather between the two main seasons spawned the sirocco, the searing east or south wind that descended sporadically from the desert, blasting vegetation (Gen 41:6; Ps 103:16; Jonah 4:8), drying up water sources, and wrecking ships at sea (Ezek 27:26). God used an east wind to dry up the Flood (Gen 8:1) and drive back the waters of the sea (Exod 14:21). Wind was a mysterious force, moving endlessly from unknown origin to unknown destination (Eccl 1:6; John 3:8). It was a symbol of transience (Ps 78:39), fruitless striving (Eccl 1:14), and empty talk (Jer 5:13), but also of untamed, irresistible power (Jer 18:17), tossing to and fro (Eph 4:14). God alone could command the winds (Mark 4:41), sending them forth from storehouses (Jer 10:13), riding upon them in the clouds (Ps 18:10; Ps 104:3; Ezek 1:4), and commissioning them to do God’s will (Exod 15:10; Ps 104:4). The Holy Spirit at Pentecost was perceived as a mighty wind (Acts 2:2), and the four winds of heaven described the extremities of the universe (Dan 7:2; Matt 24:31; Rev 7:1).