...were said whenever Jesus's antagonists tried to stump him, or force him into an uncompromising dilemma.
When the Pharisees asked Jesus whether the adulteress should be stoned, they thought they had him in a box. If Christ told them to stone her, he would've looked not like the compassionate, forgiving teacher, but someone with a cruel bent. Had Christ said not to stone the adulteress, Christ would then look permissive and indulgent. However, Jesus gave an answer that is now so recognizable that it has lost its profundity in our pop culture.
"When they kept on questioning him, he straightened up, and said to them, 'If any one of you is without sin, let him be the first to throw a stone at her'." (John 8:7). Jesus gave the most unlikely of answers, and made clear that judgment was God's, and God's alone. This story shows the forgiving nature of God. It also shows that God is a just God. There will be judgment, but there will be forgiveness for those that seek and those that accept it.
This goes for everyone. Judgment of others is not ours, but God's.
"Judge not, and ye shall not be judged: condemn not, and ye shall not be condemned, forgive, and ye shall be forgiven."
"Isn't it true that the drunkard will boast of his charity, the immoral man is thankful he's not a thief, and the profane swearer flatters himself that he never lies." -- Ravi Zacharias