1 Corinthians 9:20

"And I became," says he, "to the Jews as a Jew, that I might gain Jews." And how did this take place? When he circumcised that he might abolish circumcision. Wherefore he said not, "a Jew," but, "as a Jew," which was a wise arrangement. What sayest thou? The herald of the world and he who touched the very heavens and shone so bright in grace, doth he all at once descend so low? Yea. For this is to ascend. For you are not to look to the fact only of his descending, but also to his raising up him that was bowed down and bringing him up to himself. "To them that are under the law, as under the law, not being myself under the law, that I might gain them that are under the law." Either it is the explanation of what went before, or he hints at some other thing besides the former: calling those Jews, who were such originally and from the first: but "under the law," the proselytes, or those who became believers and yet adhered to the law. For they were no longer as Jews, yet "under the law." And when was he under the law? When he shaved his head; when he offered sacrifice. Now these things were done, not because his mind changed, (since such conduct would have been wickedness,) but because his love condescended. For that he might bring over to this faith those who were really Jews, he became such himself not really, showing himself such only, but not such in fact nor doing these things from a mind so disposed. Indeed, how could he, zealous as he was to convert others also, and doing these things only in order that he might free others who did them from that degradation?