“For if Abraham were justified by works, he hath whereof to glory; but not before God.”
King James Version (KJV)
4:2 The meaning is, If Abraham had been justified by works, he would have had room to glory. But he had not room to glory. Therefore he was not justified by works.
Ro 4:2 Hath [whereof] to glory. If Abraham was justified by his own righteous works, he would have ground for glorying in himself.