John Trapp on Matthew 14:28

Verse 28. If it be thou, bid me come unto thee, &c.] This fact of Peter some extoll, as an argument of his strong faith and love to Christ. But others of better judgement, censure it as an effect of unbelief, and rashnesse in him, requiring to be confirmed by a miracle: to the which though our Saviour assented, yet we cannot say that he approved it. The other Disciples beleeved Christ upon his bare word, but Peter must have a signe. He had it, but with a check, ver. 31.