What is the significance of the sequence of events in the current Pasuk and the following one?
Seforno: Now that (for the first time) Yitzchak built a Mizbe'ach and called out in the name of Hashem, he merited 1 that his shepherds dug a well without opposition, that Avimelech came out to visit him and enter into a covenant with him, and that from now on, the P?lishtim left him in peace.
Why did Yitzchak not give the new well a name?
Ramban (in Pasuk 32) and Rashbam: Because meanwhile, Avimelech arrived and entered into a covenant with him, and it was only afterwards that his shepherds came and informed him about it ? in Pasuk 32, at which point he named it. 1
The delay itself seems to have been an act of Hashgachah Pratis, as it was min ha'Shamayim that the well should be called 'Shiv'ah,' and the town 'Be'er-Sheva.'
Why does it say here "va'Yichru"? Below (26:32), it says "Asher Chafaru"!
Malbim and Ha'amek Davar: Yichru is the initial digging. Chafaru refers to finishing the digging. Ha'amek Davar - the Torah teaches that (a) first he built a Mizbe'ach, a place for Korban and Tefilah, and called in HaSh-m's name; (b) then he built his tent for dwelling, and (c) only after, he began digging a well, for more comfortable dwelling.
