(1 Corinthians 14:4 KJV) He that speaketh in an unknown tongue edifieth himself;
You seem to believe there is something wrong with that.
Rhema
Taken out of context, sure I do, when thru out that chapter, Paul was saying that for that tongue to benefit himself to be fruitful, he would pray while he is speaking in tongues as manifested by the Holy Ghost that the tongue would be interpreted so he would understand it.
1 Corinthians 14
:1Follow after charity, and desire spiritual gifts, but rather that ye may prophesy. 2 For he that speaketh in an unknown tongue speaketh not unto men, but unto God: for no man understandeth him; howbeit in the spirit he speaketh mysteries. 3 But he that prophesieth speaketh unto men to edification, and exhortation, and comfort. 4 He that speaketh in an unknown tongue edifieth himself; but he that prophesieth edifieth the church. 5 I would that ye all spake with tongues but rather that ye prophesied: for greater is he that prophesieth than he that speaketh with tongues,
except he interpret, that the church may receive edifying.
6 Now, brethren, if I come unto you speaking with tongues, what shall I profit you, except I shall speak to you either by revelation, or by knowledge, or by prophesying, or by doctrine? 7 And even things without life giving sound, whether pipe or harp, except they give a distinction in the sounds, how shall it be known what is piped or harped? 8 For if the trumpet give an uncertain sound, who shall prepare himself to the battle? 9 So likewise ye, except ye utter by the tongue words easy to be understood, how shall it be known what is spoken? for ye shall speak into the air. 10 There are, it may be, so many kinds of voices in the world, and none of them is without signification. 11 Therefore if I know not the meaning of the voice, I shall be unto him that speaketh a barbarian, and he that speaketh shall be a barbarian unto me.
12 Even so ye, forasmuch as ye are zealous of spiritual gifts, seek that ye may excel to the edifying of the church. 13 Wherefore let him that speaketh in an unknown tongue pray that he may interpret.
14 For if I pray in an unknown tongue, my spirit prayeth, but my understanding is unfruitful. 15 What is it then? I will pray with the spirit, and I will pray with the understanding also: I will sing with the spirit, and I will sing with the understanding also.
The actual God's gift of tongues can edify self when it is interpreted. That is what Paul was doing in comparing the gift of prophesy over the gift of tongues for why he was telling believers that are zealous for spiritual gifts to seek the gift of prophesy over all spiritual gifts, especially tongues, by comparing tongues against prophesy to show tongues is not a stand lone gift, meaning, never for private use.
And the fact that many testimonies in how they got that tongues for private use happened later in life as a saved believer, and/or sought to receive another baptism with the Holy Ghost by that sign of tongues, and/or those who came forward seeking roof of their salvation, ought to heed this waning from the Lord.
Matthew 12:39 But he answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given to it, but the sign of the prophet Jonas: 40 For as Jonas was three days and three nights in the whale's belly; so shall the Son of man be three days and three nights in the heart of the earth.
Paul gave the bottom line on tongues below that it is about God speaking unto the people in their native foreign language that His disciples know not the language in case any one should misunderstood his words.
1 Corinthians 14:20 Brethren, be not children in understanding: howbeit in malice be ye children, but in understanding be men.
21 In the law it is written, With men of other tongues and other lips will I speak unto this people; and yet for all that will they not hear me, saith the Lord. 22 Wherefore tongues are for a sign, not to them that believe, but to them that believe not: but prophesying serveth not for them that believe not, but for them which believe.
Paul did specify that the gifts were to profit the body withal & not individually in the prior chapter 12 so believers will not think otherwise, & neither are any of the gifts sought to be gained by another drink of the One Spirit apart from salvation les we depart from the testimony we are all supposed to share in verse 13 below.
1 Corinthians 12:7 But the manifestation of the Spirit is given to every man
to profit withal.
12 For as the body is one, and hath many members, and all the members of that one body, being many, are one body: so also is Christ.
13 For by one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit. 14 For the body is not one member, but many.
19 And if they were all one member, where were the body? 20 But now are they many members, yet but one body.
21 And the eye cannot say unto the hand, I have no need of thee: nor again the head to the feet, I have no need of you.
To say tongues are for private use and have no need for any one to interpret it is pretty much overlooking the reproof of such notion in verse 21.