For this Agar is mount Sinai in Arabia, and answereth to Jerusalem which now is, and is in bondage with her children. For this Agar is Mount Sinai in Arabia - Το γαρ Αγαρ Σινα ορος εστιν εν τη Αραβια. This is the common reading; but it is read differently in some of the most respectable MSS., versions, and fathers; thus: το γαρ Σινα ορος εστιν εν τῃ Αραβια, for this Sinai is a mountain of Arabia; the word Αγαρ, Agar, being omitted. This reading is supported by CFG, some others, the Ethiopic, Armenian, Vulgate, and one copy of the Itala; by Epiphanius, Damascenus, Ambrosiaster, Jerome, Augustine, Hilary, Sedulius, and Bede; and the word is sometimes, though not always, omitted by Cyril and Origen, which proves that in their time there were doubts concerning the common reading.
Of the word Agar in this verse, which renders the passage very obscure and difficult, Professor White says, forsitan delendum, "probably it should be expunged." Griesbach has left it in the text with a note of doubtfulness.
Answereth to Jerusalem - Hagar, the bond maid, bringing forth children in a state of slavery, answereth to Jerusalem that now is, συστοιχει, points out, or, bears a similitude to, Jerusalem in her present state of subjection; which, with her children - her citizens, is not only in bondage to the Romans, but in a worse bondage to the law, to its oppressive ordinances, and to the heavy curse which it has pronounced against all those who do not keep them.