In this weeks Parsha we find Israel blessing Manasseh and
Ephraim through Yosef.
In chapter 48 verse 16 Israel blessed Yosef that his
sons should yid-gu, grow like fish.
Just like fish,- ve-yid-gu= dagim. You should
grow like dagim (fish) that multiply and increase,and no evil eye has
power over them (Rashi)
Did you ever think about the word yidgu ? It means become
like a fish.