The scribes and Pharisees brought her to Jesus in the middle of His teaching. The law prescribed death; the trap was to make Him either contradict Moses or condemn her. Jesus bent down and wrote on the ground. When they kept pressing, He stood and said that the one without sin should throw the first stone. They left, one by one, the oldest first.
Then He spoke to her, the only one who had not been asked anything. He did not say the act was nothing. He said He did not condemn her, and He told her to go and not sin again. Mercy and truth arrived in the same sentence. The Church reads this scene at the heart of Lent because it is what confession is: the accusers gone, the sin named, and a way forward given.
Neither do I condemn you; go, and do not sin again.
John 8:11, RSV-CE