Galatians 3:17

3:17 What I am saying is this: The law that came four hundred thirty years later does not cancel a covenant previously ratified by God, ¹  so as to invalidate the promise.

Galatians 4:30

4:30 But what does the scripture say? “Throw out the slave woman and her son, for the son of the slave woman will not share the inheritance with the son” ²  of the free woman.

[3:17]  ¹ tc Most mss (D F G I 0176 0278 Ï it sy) read “ratified by God in Christ” whereas the omission of “in Christ” is the reading in Ì⁴⁶ א A B C P Ψ 6 33 81 1175 1739 1881 2464 pc co. The shorter reading is strongly supported by the ms evidence, and it is probable that a copyist inserted the words as an interpretive gloss. However, this form of the “in Christ” expression is somewhat atypical in the corpus Paulinum (εἰς Χριστόν [ei" Criston] rather than ἐν Χριστῷ [en Cristw]), a fact which tempers one’s certainty about the shorter reading. Nevertheless, the expression is used more in Galatians than in any other of Paul’s letters (Gal 2:16; 3:24, 27), and may have been suggested by such texts to early copyists.

[4:30]  ² sn A quotation from Gen 21:10. The phrase of the free woman does not occur in Gen 21:10.