In the Hindu religious scripture known as the Manu-smriti, we read:
Gautama (18-21).— A girl should be given in marriage before puberty.
Vashistha (17.70).— Out of fear of the appearance of the menses, let the father marry his daughter while she still runs about naked. For if she stays in the home after the age of puberty, sin falls on the father.
Bodhayana (4.1.11).— Let him give his daughter, while she still goes about naked, to a man who has not broken the vow of chastity and who possesses good qualities, or even to one destitute of good qualities ; let him not keep the maiden in his house after she has reached the age of puberty.
(Manu IX, 88; http://www.payer.de/dharmashastra/dharmash083.htm)
The Encyclopedia of Religion and Ethics says:
“[It was considered] sinful on the part of the [Hindu] father to allow his daughter to attain puberty without being married and the girl herself fell to the condition of a Sudra [i.e. low caste], marriage with whom involved degradation on the part of the husband…the Smrti of Manu fixes the age of husband and wife at 30 and 12 or 24 and 8 respectively; the later work of Brhaspati and the didactic portion of the Mahabharata give the wife’s age in these cases as 10 and 7 respectively, while yet later texts give 4 to 6 as the lower and 8 as the upper limit. There is abundant evidence that these dates were not merely theoretical.”
(Encyclopedia of Religion and Ethics, p.450,