Matthew Poole and continuators on 1 Corinthians 14:16

16 Else, when thou shalt bless with the spirit , how shall he that occupieth the room of the unlearned, say Amen at thy giving of thanks , seeing he understandeth not what thou sayest?

Blessing is expounded in the latter part of the verse, giving of thanks to God, which is either in Prayer, (for Thanksgiving is a part of Prayer) or in singing of Psalms. Blessing with the Spirit either signifieth giving of thanks with the inward man, or giving of thanks in an unknown Tongue, by the extraordinary influence of the Spirit of God.

It is plain from hence, 1. That the Teachers had in the Apostolical Churches distinct places and seats from the common Hearers, for their better conveniency in speaking, that they might so speak, as all might hear, understand, and be profited. 2. That in those Churches there was one only who used to speak audibly, and the work of the others was only from a devout heart to say Amen, wishing or praying, that God would do what in the name of all, he that ministred, had asked of God for them. So 1 Chron. 16.36. Nehem. 5.13. & 8.6. Psal. 106.48.

People ought not to say Amen to any thing, but to understand that Petition, or those Petitions to which, in the Worship of God, they added their Amen, which word made the Petitions theirs, being a Particle of wishing, as well as affirming.