Local council, and not binding. There were married priests for much longer than that. The concern was that many places the priesthood risked becoming hereditary, and the income and land becoming like a local baron’s. The celibacy rule was to try to keep the control of church land under bishops
This is definitely not the case and my point was that priestly celibacy dates from apostolic times, the Council of Elvira, in the 3rd century, being one very early example of mandatory imposition of celibacy, albeit local.
It is entirely incorrect to say that "celibacy was instituted 900 years after the death of Our Lord".