Albert Barnes Commentary 1 Corinthians 14:16

"Else if thou bless with the spirit, how shall he that filleth the place of the unlearned say the Amen at thy giving of thanks, seeing he knoweth not what thou sayest?" — 1 Corinthians 14:16 (ASV)

Else. The Greek word is epei, meaning 'since.' If this is not done, and if what is said is not intelligible, how can the unlearned appropriately express his assent and join in your devotions?

When thou shalt bless. This means when you shall bless God, or give thanks to Him. It refers to when you shall lead the devotions of the people in expressing thanksgiving for mercies and favours.

This may refer to a part of public worship, or to the thanks that should be expressed at the table, and the invocation of the divine blessing to accompany the bounties of His providence.

Paul had illustrated his subject by prayer and by singing; he now does so by a reference to the important part of public worship expressed in giving thanks.

With the spirit. This means in the manner referred to above; that is, in an unknown tongue, in such a way that your own heart may be engaged in it, but which would be unintelligible to others.

He that occupieth the room. This refers to one who is in the place, or the seat, of the unlearned; that is, someone who is unlearned. For the meaning of the word room, see the notes on Luke 14:8.

To fill a place means to occupy a station, or to be in a particular state or condition.

Of the unlearned, tou idiwtou. For the meaning of this word, see the notes on Acts 4:13.

Here it means one who was unacquainted with the foreign language spoken by the one who gave thanks. It properly denotes a person in private life, in contrast to a person in public life, and therefore someone who is ignorant and unlettered, as such individuals generally were.

Say Amen. This word means truly, verily, and is an expression of affirmation (John 3:6) or of assent. Here it means assent.

How can he pronounce the AMEN? How can he express his assent? How can he join in the act of devotion? This might have been, and probably was, expressed aloud, and there is no impropriety in it.

It may, however, be mental—a silent assent to what is said and a silent uniting in the act of thanksgiving. In one way or the other, or in both, assent should always be expressed by those who join in acts of public worship.