John Gill, on Esth 2:16

So Esther was taken unto King Ahasuerus, into his house royal,.... Did not return on the morrow to the house of the women, as those who only became the king's concubines did, Est 2:14, but she was taken to be his wife, and designed for his queen, and so was retained in his palace, and placed in an apartment suitable to the dignity she was about to be advanced unto: and this was done in the tenth month, which is the month Tebeth; and answers to part of December and part of January; not the twelfth month Adar, as the Septuagint version, and so Josephus (q), contrary to the original text: either that law had not obtained among the Persians, or the king thought himself not bound by it, which forbid marriage at any other time than the beginning of the vernal equinox (r): in the seventh year of his reign; and the divorce of Vashti being in the third year of his reign, it was four years before Esther was taken by him; who, if Xerxes, it may be accounted for by his preparation for, and engagement in, a war with Greece, which took him up all this time; and from whence he returned in the seventh year of his reign, at the beginning of it, and married Esther at the close of it, see Est 2:1 as may be suggested. (q) Ut supra (Antiqu. l. 11. c.6. sect. 2.) (r) Strabo. Geograph. l. 1. p. 504.