The sanctification of chrism may, in theory, be performed by any bishop at any time, but in longstanding practice is performed no more than once a year by hierarchs of most of the autocephalous churches, although some autocephalous churches obtain their chrism from another church. Anointing with it substitutes for the laying-on of hands described in the New Testament, and according to the prayer of consecration of chrism, the apostles made the initial chrism, laying their hands on it, for priests to substitute for laying on of hands for sundry practices, where only the apostles could perform said laying on of hands.