Wherefore do the wicked {d} live, become old, yea, are mighty in power?

(d) Job proves against his adversaries that God does not punish the wicked immediately, but often gives them long life and prosperity, so we must not judge God just or unjust by the things that appear to our eyes.

Jamieson-Fausset-Brown Bible Commentary

7. The answer is Ro 2:4; 1Ti 1:16; Ps 73:18; Ec 8:11-13; Lu 2:35-end; Pr 16:4; Ro 9:22.

old-in opposition to the friends who asserted that sinners are "cut off" early (Job 8:12, 14).

Matthew Henry's Concise Commentary

21:7-16 Job says, Remarkable judgments are sometimes brought upon notorious sinners, but not always. Wherefore is it so? This is the day of God's patience; and, in some way or other, he makes use of the prosperity of the wicked to serve his own counsels, while it ripens them for ruin; but the chief reason is, because he will make it appear there is another world. These prospering sinners make light of God and religion, as if because they have so much of this world, they had no need to look after another. But religion is not a vain thing. If it be so to us, we may thank ourselves for resting on the outside of it. Job shows their folly.