Albert Barnes Commentary Job 42:2

"I know that thou canst do all things, And that no purpose of thine can be restrained." — Job 42:2 (ASV)

I know that you can do everything - This is said by Job in view of what had been declared by the Almighty in the previous chapters. It is an acknowledgment that God was omnipotent, and that man ought to be submissive under the exercise of his infinite power. One great object of the Almighty's address was to convince Job of his majesty, and that object was fully accomplished.

And that no thought - No purpose or plan of yours. God was able to execute all his designs.

Can be withheld from you - Margin, “or, of yours can be hindered.” Literally, “cut off” - בצר bâtsar. The word, however, also means “to cut off access to,” and then to prevent, hinder, restrain. This is its meaning here; so (Genesis 11:6), “Nothing will be restrained (יבצר yibâtsar) from them, which they have imagined to do.”