The New John Gill Exposition of the Entire BibleGenesis 48:8
And Israel beheld Joseph's sons…
Ephraim and Manasseh, of
whom he had been speaking as if they were absent, and he might not know
until now that they were present, for his eyes were dim that he could
not see clearly, (Genesis 49:10) ; he saw two young men standing by Joseph,
but knew not who they were, and therefore asked the following question:
and said, who [are] these?
whose sons are they? the Targum of Jonathan
``of whom were these born to thee?''
as if he knew them to be his sons, only inquired who the mother of them
was; but the answer shows he knew them not to be his sons, and as for
his wife, he could not be ignorant who she was.