ישעיהו ל:כג פירוש: רש״י ואבן עזרא

And He shall give I.e., the Holy One, blessed be He, shall give the rain for your seed.

Then shall he give, etc., that thou shalt sow, after the death of the King of Assyria.

fat (וְשָׁמֵן) an expression of fat. Therefore, its accent is below (on the last syllable) and it is voweled with a kamatz (tzeireh).