Why was it mentioned in verse 146 of Surat Al-Baqarah: (Those to whom We gave the Scripture know him as they know their own sons), and not mentioned "as they know themselves"?

Allah Almighty stated that the People of the Book knew the Prophet, peace and blessings be upon him, as they knew their own sons. The wisdom behind this is that a man knows the details and stages of his son's life more intimately than he knows about himself, because he does not witness himself in all the early stages of his life. Al-Tabari mentioned that the People of the Book from Medina who embraced Islam said: "By Allah, we know him better than our own sons, because of the description and characteristics we find in the Book, whereas we do not know what our wives have done concerning our sons." Al-Qurtubi and Ibn Ashour were of the view that the specific mention of sons is due to the strong attachment fathers have to them, and seeing them frequently, which makes their knowledge firm and well-established.