Jehoiachin was eighteen years old when he began to reign,.... In 2Ch 36:9 he is said to be but eight years old; which may be reconciled by observing, that he might be made and declared king by his father, in the first year of his reign, who reigned eleven years, so that he was eight years old when he began to reign with him, and eighteen when he began to reign alone .
Dr. Lightfoot gives another solution of this difficulty, that properly speaking he was eighteen years old when he began to reign, but, in an improper sense, the son of eight years, or the eighth year, as the Hebrew phrase is; that is, he fell in the lot of the eighth year of the captivity of Judah, which was in the latter end of the third, or the beginning of the fourth of his father's reign, and the first of Nebuchadnezzar's, and it was now in the eighth of Nebuchadnezzar that he was king, see 2Ki 24:12, but very probably in 2Ch 36:9 there is a mistake in the copyist of eight for eighteen, since in the Arabic and Syriac versions it is there eighteen, as here:he reigned in Jerusalem three months; the ten days besides are here omitted for shortness, 2Ch 36:9and his mother's name was Nehushta, the daughter of Elnathan of Jerusalem; a person no doubt well known in those times.
So in Seder Olam Rabba, c. 25. Works, vol. 1. p.