John Chrysostom, on 1Cor 14:39

Then, as he is ever wont to do, unto the former subject whence he digressed to say these things, he brings back his discourse as follows:

"Wherefore, brethren, desire earnestly to prophesy, and forbid not to speak with tongues."

For this too is his wont, not only to work out what is before him, but also starting from that to set right whatever seems to him in any way akin to it, and again to return to the former, so as not to appear to wander from the subject. For so when he was discoursing of their concord in their banquets, he digressed to their Communion in the Mysteries, and having thence put them to shame, he returns again to the former, saying, "Wherefore, when ye come together to eat, wait one for another." (1 Cor. 11:33)

And here, accordingly, having discoursed of good order in their gifts, and of its being a duty neither to faint in the lesser, nor to be puffed up on account of the greater; then having made an excursion from thence to the sobriety becoming women and having established it, he returns again to his subject, saying, "Wherefore, brethren, desire earnestly to prophesy, and forbid not to speak with tongues." Seest thou how to the end he preserved the difference of these? And how he signifies that the one is very necessary, the other not so? Wherefore of the one he saith, "desire earnestly," but of the other, "forbid not."