Note that Righteouswrath says the KJV is not OK for a particular verse he doesn't like but OK for other parts of the OT and for the NT. Do not trust the advice of this person. He is picking and choosing to match his beliefs. What gives him the special dispensation to say this version for this verse and this for another. Does he read Hebrew fluently so he can read it in the original. What criteria other than his own preconceived beliefs does he have for making such judgments. As I have shown he picks for these verses in Numbers a version that disagrees with 22 other versions. That should give one pause.....

This is also discussed in detail in the posted link:

Children as Concubines, Babies as Wives

The ancient Hebrews were permitted to use children as concubines. Moses established the precedent. In the passage below, the Hebrews have just massacred the Midianite men. They return home with booty, and the Midianite women and children. Moses directs them to slaughter the captive women and children with this exception: virgin girl children are to be kept as concubines for the Hebrews.

    And they brought the captives, and the prey, and the spoil, unto Moses, and Eleazar the priest, and unto the congregation of the children of Israel, unto the camp at the plains of Moab, which are by Jordan near Jericho.
    And Moses, and Eleazar the priest, and all the princes of the congregation, went forth to meet them without the camp.
    And Moses was wroth with the officers of the host, with the captains over thousands, and captains over hundreds, which came from the battle.
    And Moses said unto them, Have ye saved all the women alive?
    Behold, these caused the children of Israel, through the counsel of Balaam, to commit trespass against the LORD in the matter of Peor, and there was a plague among the congregation of the LORD.
    Now therefore kill every male among the little ones, and kill every woman that hath known man by lying with him.
    But all the women children, that have not known a man by lying with him, keep alive for yourselves. 

— Numbers 31:12-18 (KJV)

In the following, the Talmud Sages reason that, since Phinehas was among the Hebrews who were permitted a child concubine and Phinehas was a priest, Numbers 31:17-18 is Divine sanction for the marriage of priests with girls under the age of three — babies. The rabbis describe the babies as proselytes. The American Heritage Dictionary defines proselyte as "a Gentile converted to Judaism." In the following passage, a bondman is a male slave, and a bondwoman a female slave.

GEMARA. … It was taught: R. Simeon b. Yohai stated: A proselyte who is under the age of three years and one day is permitted to marry a priest, (2) for it is said, But all the women children that have not known man by lying with him, keep alive for yourselves, (3) and Phinehas (4) surely was with them. And the Rabbis? (5) — [These were kept alive] as bondmen and bondwomen. (6) If so, (7)  a proselyte whose age is three years and one day (8) should also be permitted! — [The prohibition is to be explained] in accordance with R. Huna. For R. Huna pointed out a contradiction: It is written, Kill every woman that hath known man by lying with him, (9) but if she hath not known, save her alive; from this it may be inferred that children are to be kept alive whether they have known or have not known [a man]; and, on the other hand, it is also written, But all the women children, that have not known man by lying with him, keep alive for yourselves, (3) but do not spare them if they have known. Consequently (10) it must be said that Scripture speaks of one who is fit (11) for cohabitation. (12)

— Babylonian Talmud, Tractate Yebamoth 60b Soncino 1961 Edition, page 402

This is a special definition of cohabitation. The translator, Rev. Dr. Israel W. Slotki, amplifies the text with footnotes:

    She is not regarded as a harlot.
    Num. XXXI, 18.
    Who was a priest.
    How could they, contrary to the opinion of R. Simeon b. Yohai, which has Scriptural support, forbid the marriage of the young proselyte?
    Not for matrimony.
    That, according to R. Simeon, Num. XXXI, 18 refers to matrimony.
    So long as she has 'not known man'.
    Num. XXXI, 17.
    To reconcile the contradiction.
    I.e., one who had attained the age of three years and one day.
    Not one who had actually experienced it. 

— Rev. Dr. Slotki

The doctrine that Jewish men may have sexual intercourse with non-Jewish children ("proselytes") under the age of three is expanded in the following passage; "Rabbi" is Judah the Prince.

GEMARA. … R. Jacob b. Idi stated in the name of R. Joshua b. Levi: The halachah is in agreement with R. Simeon b. Yohai. (13) Said R. Zera to R. Jacob b. Idi: Did you hear this (13) explicitly or did you learn it by a deduction? What [could be the] deduction? — As R. Joshua b. Levi related: There was a certain town in the Land of Israel the legitimacy of whose inhabitants was disputed, and Rabbi sent R. Romanos who conducted an enquiry and found in it the daughter of a proselyte who was under the age of three years and one day, (14) and Rabbi declared her eligible to live with a priest. (15) 

— Babylonian Talmud, Tractate Yebamoth 60b Soncino 1961 Edition, page 403

The translator, Rev. Dr. Israel W. Slotki, amplifies the text with footnotes:

    That a proselyte under the age of three years and one day may be married by a priest.
    And was married to a priest.
    I.e., permitted her to continue to live with her husband. 

— Rev. Dr. Slotki

Not every Sage agreed with this practice. The Talmud records the words of one Sage who objected to one case, though it does not record the specifics of his objection.

GEMARA. … A certain priest married a proselyte who was under the age of three years and one day. Said R. Nahman b. Isaac to him: What [do you mean by] this? (12) — The other replied: Because R. Jacob b. Idi stated in the name of R. Joshua b. Levi that the halachah is in agreement with R. Simeon b. Yohai. (13) 'Go', the first said, 'and arrange for her release, or else I will pull R. Jacob b. Idi out of your ear'. (14)

— Babylonian Talmud, Tractate Yebamoth 60b Soncino 1961 Edition, page 404

The translator, Rev. Dr. Israel W. Slotki, amplifies the text with footnotes:

    I.e., on what authority did you contract the marriage.
    V. supra p. 403. n. 13.
    He would place him under the ban and thus compel him to carry out his decision which is contrary to that of R. Jacob b. Idi. 

— Rev. Dr. Slotki

The teachings are pervy.

It's always amazed me that men have never organized together to stop the insanity of male circumcision .... that would be one place to begin.