to grow vast, whether in numbers or in strength
This is a word about growth that gets out of hand. It describes a people, an army, a run of troubles, or a tally of sins swelling until they are simply too great to reckon with. Sometimes the greatness is a matter of numbers, sometimes of raw power, and often the two run together: a nation that keeps multiplying also becomes hard to defeat.
Because the one Hebrew word can lean either way, translators have to decide in each verse whether the point is "so many" or "so strong." When Israel swells in Egypt the word is paired with the ordinary verb for multiplying (רָבָה), and the two together picture a population exploding past all control. Elsewhere it is a person's enemies, or a king's power, that has grown overwhelming.
The same word can be turned outward. Instead of a people growing strong on its own, God is the one who makes them strong, building them up until they outmatch their rivals.