Since you are in pursuit of spiritual gifts Paul concludes that the gift of tongues has not been conferred with the view of giving occasion of boasting to a few, without yielding advantage to the Church. "If spiritual gifts," says he, "delight you, let the end be edification. Then only may you reckon, that you have attained an excellence that is true and praiseworthy -- when the Church receives advantage from you. Paul, however, does not hereby give permission to any one to cherish an ambition to excel, even to the benefit of the Church, but by correcting the fault, he shows how far short they come of what they are in pursuit of, and at the same time lets them know who they are that should be most highly esteemed. He would have a man to be held in higher estimation, in proportion as he devotes himself with eagerness to promote edification. In the meantime, it is our part to have this one object in view -- that the Lord may be exalted, and that his kingdom may be, from day to day, enlarged. The term spirits, [1] he employs here, by metonymy, to denote spiritual gifts, as the spirit of doctrine, or of understanding, or of judgment, is employed to denote spiritual doctrine, or understanding, or judgment. Otherwise we must keep in view what he stated previously, that it is one and the same Spirit, who distributeth to every man various gifts according to his will. (1-Corinthians 12:11.)

Footnotes

1 - "Les dons spirituels, il y a mot a mot, les esprits;" -- "Spiritual gifts -- it is literally, spirits."

Even so ye - Since you desire spiritual gifts, I may urge it upon you to seek to he able to speak in a clear and intelligible manner, that you may edify the church. This is one of the most valuable endowments of the Spirit; and this should be earnestly desired.
Forasmuch as ye are zealous - Since you earnestly desire; See the note at 1-Corinthians 12:31.
Spiritual gifts - The endowments conferred by the Holy Spirit; See the note at 1-Corinthians 12:1.
Seek that ye may excel - Seek that you may be able to convey truth in a clear and plain manner; seek to be distinguished for that. It is one of the most rare and valuable endowments of the Holy Spirit.

For as much as ye are zealous - Seeing ye affect so much to have spiritual gifts, seek that ye may get those by which ye may excel in edifying the Church.

(5) Even so ye, forasmuch as ye are zealous of spiritual [gifts], seek that ye may excel to the edifying of the church.
(5) The conclusion: if they will excel in those spiritual gifts, as it is proper, they must seek the profit of the church. And therefore they must not use the gift of tongues, unless there is an interpreter to expound the strange and unknown tongue, whether it is himself that speaks, or another interpreter.

Even so ye, forasmuch as ye are zealous of spiritual gifts,.... Gr. "of spirits"; that is, "of the gifts of the Spirit", as the Syriac version renders it; and we rightly, "spiritual gifts"; the extraordinary gifts of the Spirit, for which the apostle does not blame them; these being what he had before exhorted them to covet earnestly, and zealously affect and desire: but then he further advises,
seek that ye may excel, to the edifying of the church: above all, be desirous of such gifts, and of excelling in them, and abounding in the exercise of them, which may be most profitable and edifying to the members of the church; and what these were, and in what manner to be used, he had before signified: the Alexandrian copy reads, seek that ye may prophesy.

zealous--emulously desirous.
spiritual gifts--literally, "spirits"; that is, emanations from the one Spirit.
seek that ye may excel to--Translate, "Seek them, that ye may abound in them to the edifying," &c.

Seek that ye may excel to the edifying of the church. If you seek for spiritual gifts, seek rather those that will build up the church, such as prophesying and teaching.
Wherefore let him that speaketh in an unknown tongue. Let him pray that he may have the gift of interpretation also. See 1-Corinthians 12:10. Let him pray that he may understand what he utters, so as to explain it.
If I pray in an unknown tongue. He does not understand, and only his spirit prayeth.
What is it then? How then am I to act? He answers that question. He will have both the spirit and the understanding unite in singing and praying, by using a tongue that he understands.
Else, when thou shalt bless the Spirit, etc. If an unknown tongue is used, how can one who does not understand it say the Amen to the blessing at the proper place? Note here, (1) This shows that audible responses to the praises and thanksgivings were the custom of the church. (2) The unlearned means a private person, the private members of the church, those not possessed of the spiritual gifts.