Saint Chrysostom adds this by interpreting the words food no one from the catechumens. He says: this means that none of those unworthy to eat the Divine meal, none of those unworthy to see the heavenly blood shed for the remission of sins, none of those unworthy of the living sacrifice; none of those who did not know the mysteries of faith, none of those who could touch the terrible Mysteries with defiled lips, dared to remain in the church at this time! Therefore, this exclamation obviously has full force and application to everyone present in the church at that time.
In the primal Church, the Liturgy of the catechumens was celebrated in the church among the people, and upon the announcement of the catechumens, the priest entered the altar to celebrate the Liturgy of the faithful.