Commentaire sur La Genèse 48:8

וירא ישראל את בני יוסף AND ISRAEL SAW JOSEPH’S SONS — he wished to bless them but the Divine Presence departed from him because he saw that from Ephraim would be born the wicked kings Jeroboam and Ahab, and from Manasseh Jehu and his sous (Midrash Tanchuma, Vayechi 6).

וירא ישראל, even though we have been told that Yaakov could not see well due to his age (verse 10), it is possible for people whose eyesight has become dimmed to recognise the silhouette of a person without being able to distinguish his facial features sufficiently to identify them. When G’d told Moses that it was impossible for man to “see” Him (Exodus 33,20), He did not mean that man is unable to see any aspect of G’d. This is why the prophet Michyahu could claim to have “seen” G’d (Kings I 22,19) without this being a contradiction to what is written in Exodus 33,20. [thus invalidating King Menashe ordering the execution of the prophet Isaiah for being a false prophet based on his saying that he had “seen” (Isaiah 6,1) G’d. Ed.]

וירא ישראל את בני יוסף, he recognised them as human beings, but did not recognise them for who they were.