Isaac, though called a lad, Genesis 22:5, was now a grown man, at least five and twenty years old, and therefore well able to bear that burden; and in this act he was an eminent type of Christ, who carried that wood upon which he was crucified.
Related Commentaries of Genesis 22:6
Genesis 22:6
6 And Abraham took the wood of the burnt offering, and laid it upon Isaac his son; and he took the fire in his hand, and a knife; and they went both of them together.