In the entire Parshah, it says "Yitzchak Beno." Why does it say here just "Beno"?
Shulchan Gavoha, citing R. Eliyahu Lopi'an: When he was ready to slaughter him, the mercy of a father was aroused. 1
Bereishis Rabah 56:8 says that Avraham's tears were falling into Yitzchak's eyes. Even so, Avraham's heart was happy to carry out Hashem's will!
Why does it use an expression of Shelichus for taking the knife?
Ha'Kesav veha'Kabalah: He did not take it lazily and without desire, rather, with Zerizus.
An Olah is not slaughtered on the Mizbe'ach. Why did Avraham intend to do so?
Tzafnas Pane'ach: After the Shechitah, Avraham would be an Onen (one whose relative died), and could not perform the other Avodos 1 , so he planned to slaughter him where he will be burned.
Tzitz Eliezer (15:6): First Avraham did what he was commanded explicitly - to bring him up (on the Mizbe'ach) for an Olah - before what he understood was Hashem's intent (Shechitah and Hakravah).
Tzitz Eliezer rejects this, for Midrashim say that Avraham had the status of a Kohen Gadol, who may offer b'Aninus.