From Parashat Toldot
The Torah devotes three parshiyot to Avraham (Lech Lecha, Vayera, and Chayei Sara) and the balance of Bereshit (from Vayetze to Vayachi) deals with Yaakov and the twelve tribes. Toldot is the sole parasha that teaches us about Yitzchak's life.
Q: Is Yitzchak the patriarch we never quite got to know? Why such scant and skeletal treatment for him? After all, Yitzchak, uniquely, is referred to as a pure, burnt offering ('korbon olah'). Recall, that designation precluded his leaving Canaan – even when it came to choosing his own bescherte.
A: The Torah's crafted brevity, always present, is particularly glaring here. Understanding the parasha's first verse – seemingly repeating itself purposelessly – holds the key.
‘These are the life events of Yitzchak, son of Avraham: Avraham was Yitzchak's father.’
In Hebrew, the word 'life events' (toldot) has a double meaning. It denotes offspring as well as major life events. The Torah depends on, even expects, readers to do their homework and investigation. Specifically, the Torah nudges students to chart just how closely Yitzchak's life tracked the pattern of his father Avraham. Abravanel lists FOURTEEN such similarities!
Both men married women from their extended families. Both married at forty etc.
In the final analysis, the Torah does not, of course, minimize or truncate Yitzhak's stature or accomplishments. But here's the thing. The second patriarch's greatness, though not written explicitly, just the same is chiseled into the Chosen People's moral DNA coding. Tenacious students glean much about Yitzchak through the simple, but profound phrase: ‘Avraham was Yitzchak's father.’
Indeed, much is known about Yitzchak by deduction despite the dearth of explicit, written word. His portrait, an exquisite masterpiece, is painted by way of association to his illustrious father.