John Calvin Commentary 1 Peter 3:10

"For, He that would love life, And see good days, Let him refrain his tongue from evil, And his lips that they speak no guile:" — 1 Peter 3:10 (ASV)

For he. He confirms the last sentence by the testimony of David. The passage is taken from the thirty-fourth Psalm (Psalms 34:12–16), where the Spirit testifies that it will be well with all who keep themselves from all evil-doing and wrongdoing. The common feeling indeed favors what is very different, for people think that they expose themselves to the insolence of enemies if they do not boldly defend themselves. But the Spirit of God promises a happy life only to the meek and those who endure evils; and we cannot be happy unless God prospers our ways. It is the good and the benevolent, and not the cruel and inhuman, that he will favor.

Peter has followed the Greek version, though the difference is slight. David’s words are literally these: “He who loves life and desires to see good days,” etc. It is indeed a desirable thing, since God has placed us in this world, to pass our time in peace. Then, the way of obtaining this blessing is to conduct ourselves justly and harmlessly towards all.

He first points out the vices of the tongue, which are to be avoided, so that we are not scornful and insolent, nor speak deceitfully and with duplicity. Then he comes to deeds: that we are to injure no one or cause loss to no one, but to endeavor to be kind to all and to exercise the duties of humanity.