"He who is without sin among you, let him throw a stone at her first"
"Now early in the morning He came again into the temple, and all the people came to Him; and He sat down and taught them. Then the scribes and Pharisees brought to Him a woman caught in adultery. And when they had set her in the midst, they said to Him, 'Teacher, this woman was caught in adultery, in the very act. Now Moses, in the law, commanded us that such should be stoned. But what do You say?' This they said, testing Him, that they might have something of which to accuse Him. But Jesus stooped down and wrote on the ground with His finger, as though He did not hear. So when they continued asking Him, He raised Himself up and said to them, 'He who is without sin among you, let him throw a stone at her first.' And again He stooped down and wrote on the ground. Then those who heard it, being convicted by their conscience, went out one by one, beginning with the oldest even to the last. And Jesus was left alone, and the woman standing in the midst. When Jesus had raised Himself up and saw no one but the woman, He said to her, 'Woman, where are those accusers of yours? Has no one condemned you?' She said, 'No one, Lord.' And Jesus said to her, 'Neither do I condemn you; go and sin no more'" (John 8:2-11 NKJ).
Thayer's Bible Dictionary renders this world "sinless; used on one who has not sinned; used of one who cannot sin". And in Jesus' response to the woman we can observe the paradox that while we are not to judge and condemn the sinner -- primarily because of the conditions of growth and development that necessitated what man portrays as sin.