(יט) וְאֵלֶּה תּוֹלְדֹת יִצְחָק בֶּן אַבְרָהָם אַבְרָהָם הוֹלִיד אֶת יִצְחָק. (כ) וַיְהִי יִצְחָק בֶּן אַרְבָּעִים שָׁנָה בְּקַחְתּוֹ אֶת רִבְקָה בַּת בְּתוּאֵל הָאֲרַמִּי מִפַּדַּן אֲרָם אֲחוֹת לָבָן הָאֲרַמִּי לוֹ לְאִשָּׁה.
(19) And these are the generations of Isaac, Abraham’s son: Abraham begot Isaac. (20) And Isaac was forty years old when he took Rebekah, the daughter of Bethuel the Aramean, of Paddan-aram, the sister of Laban the Aramean, to be his wife.
Why does this first verse seem to say the same thing twice?
“and these are the generations of Isaac” – this is the account of Isaac’s life, that “Abraham begat Isaac” – that in everything Isaac did throughout his life, it was apparent that he was Abraham’s son - Ha-Amek Davar
How was it obvious that Isaac was Abraham's son?
...We are told in Baba Metzia 86 that Isaac’s facial features were so similar to those of his father that anyone ever encountering Isaac immediately knew that he must be the son of Avraham.... Isaac possessed the same virtues and wonderful qualities which Avraham excelled in, so that it was clear who must have been his father not only physically, but that the same father also transmitted a spiritual legacy to his son.- RADAK
Who is wise? He who foresees what will take place (literally, “what will be born” – Tamid 32a). From the person who is born, the son, one can see the father. Abraham begat Isaac. - R’Bunim of Pshischa
How would this make you feel? How do you think this made Isaac feel?