Because it is contained in Scripture, "Behold, I lay in Zion a chief cornerstone, chosen, and precious: He who believes in him will not be disappointed."
But as the other reading seems to come nearer to Peter’s interpretation, I give it the preference. Then the sense would not be unsuitable, “He who believeth shall not waver” or vacillate; for he has a firm and permanent foundation. And it is a valuable truth, that relying on Christ, we are beyond the danger of falling. Moreover, to be ashamed (pudefieri ) means the same thing. Peter has retained the real sense of the Prophet, though he has followed the Greek version. (22) 