John Calvin on Hebrews 13:7

7. Remember, etc. What follows refers not so much to morals as to doctrine. He first sets before the Jews the example of those by whom they had been taught; and he seems especially to speak of those who had sealed the doctrine delivered by them by their own blood; for he points out something memorable when he says, considering the end of their conversation; though still there is no reason why we should not understand this generally of those who had persevered in the true faith to the end, and had rendered a faithful testimony to sound doctrine through their whole life as well as in death. But it was a matter of no small importance, that he set before them their teachers for imitation; for they who have begotten us in Christ ought to be to us in the place as it were of fathers. Since then they had seen them continuing firm and unmoved in the midst of much persecutions and of various other conflicts, they ought in all reason to have been deeply moved and affected. See Appendix D 3.