John 8:6

Punishment of death for this offence was obsolescent, and some think that they wished to make Jesus unpopular with the people by inducing Him to advocate its revival. More probably they wished to embroil Him with the Roman authorities, who would not allow a death-sentence to be executed without their permission. The displeasure of Jesus was largely due to the officiousness of the accusers. It was not their business to accuse and judge the woman, but that of the husband and the judges. They had neither a legal nor a moral right to interfere. Wrote] Christ was always reluctant to interfere in civil disputes: see Matthew 22:21; Luke 12:13; John 18:36. Writing on the ground was a symbolical action well known in antiquity, signifying unwillingness to deal with the matter in hand.