Esias 39:7

7 that they shall take also of thy children whom thou shalt beget; and they shall make them eunuchs in the house of the king of the Babylonians.

Esias 39:7 In-Context

5 And Esaias said to him, Hear the word of the Lord of hosts:
6 Behold, the days come, when they shall take all the in thine house, and all that thy fathers have gathered until this day, shall go to Babylon; and they shall not leave anything at all: and God hath said,
7 that they shall take also of thy children whom thou shalt beget; and they shall make them eunuchs in the house of the king of the Babylonians.
8 And Ezekias said to Esaias, Good is the word of the Lord, which he hath spoken: let there, I pray, be peace and righteousness in my days.

The Brenton translation of the Septuagint is in the public domain.