You shall count for yourselves . . . from the day on which you bring the Omer offering, seven complete weeks they shall be . . .
The word sefirah
, “counting,” also means “luminance.” On each of the 49 days of Sefirat HaOmer (the counting of the Omer), we refine, rarify and illuminate another of the forty-nine traits of our souls.
(Rabbi DovBer, the Maggid of Mezeritch)