תהילים קלה:ז פירוש: רש״י

He made lightning for the rain They are the flashes in the sky, that flash and lighten before the rain; esloyde, esluyde, esludes, esloisdes, aleydonz in Old French.

He finds Heb. מוצא, an expression of finding. i.e., He prepared a treasury for the wind, and there they are accessible to Him to send them on His mission.