To ‘edify himself’ is to be in a certain spiritual state of the descent of the Ho y Spirit, which is beneficial for the individual's edification. There are two remarks mentioned by St. Paul about this state. They are:
(a) The person should keep silent just as in any private spiritual state between oneself and God. The Apostle says: “...let him keep silent in church, and let him speak to himself and to God” (v.28). It is a matter between him and God, more suitable for him to stay in his closet and not in church in front of people. Thus speaking in a tongue will be a kind of prayer. Even so: