“And they which heard it, being convicted by their own conscience, went out one by one, beginning at the eldest, even unto the last: and Jesus was left alone, and the woman standing in the midst.”
And they which heard it, being convicted by their own conscience, went out one by one, beginning at the eldest, even unto the last: and Jesus was left alone, and the woman standing in the midst — the authorities are 'convicted by their own conscience' (elenchthentes), a work of internal judgment. Rather than defend their position, they depart 'one by one, beginning at the eldest.' The eldest leave first, perhaps a sign of greatest conviction or recognition that they cannot maintain their moral position. The description is psychologically penetrating: conscience (syneidēsis) operates where Law cannot. Jesus is left alone with the woman—the accusers are gone, and the trap is broken.
Church Fathers on John 8:9
Our Lord at the time of His passion used to spend the day in Jerusalem, preaching in the temple, and performing miracles, and return in the evening to Bethany, where He lodged with the sisters of Lazarus. Thus on the last day of the feast, having, according to His wont, preached the whole day in the temple, in the evening He went to the mount of Olives.
And where ought Christ to teach, except on the mount of Olives; on the mount of ointment, on the mount of chrism. For the name Christ is from chrism, chrism being the Greek word for unction. He has anointed us, for wrestling with the devil.
And next it is signified, that after He began to dwell by grace in His temple, i.e. in the Church, men from all nations would believe in Him: And all the people came to Him, and He sat down and taught them.