Charles Ellicott Commentary 2 Kings 20:18

"And of thy sons that shall issue from thee, whom thou shalt beget, shall they take away; and they shall be eunuchs in the palace of the king of Babylon." — 2 Kings 20:18 (ASV)

Thy sons ... beget — that is, your descendants. Compare to the fulfillment (Daniel 1:3). Ewald refers to the captivity of Hezekiah’s own son Manasseh (2 Chronicles 33:11).

Eunuchs. — Rather, courtiers, palace attendants (so Josephus). Cheyne, “chamberlains” (so Thenius: kämmerer).