John the Apostle
John 20:24ESV·traditional attribution

Now Thomas, one of the twelve, called the Twin, was not with them when Jesus came.

John Calvin Reformed @genevareformer

24. But Thomas, one of the twelve. The unbelief of Thomas is here related, that by means of it the faith of the godly may be more fully confirmed. He was not only slow and reluctant to believe, but even obstinate. His dulness of apprehension was the reason why Christ again permitted them both to see and to feel him, in the same manner as before.

Matthew Henry Presbyterian @wholebiblehenry

The infallible proof of Christ's resurrection was his showing himself alive, Act 1:3. In these verses, we have an account of his first appearance to the college of the disciples, on the day on which he rose. He had sent them the tidings of his resurrection by trusty and credible messengers; but to show his love to them, and confirm their faith in him, he...

Commenting on John 20:19-25

John Gill Reformed Baptist @doctorgill

But Thomas, one of the twelve, called Didymus,.... The person here spoken of, is described by his Hebrew name Thomas, and his Greek one Didymus, which both signify a twin; and perhaps he was one. It was common with the Jews to have two names, a Jewish and a Gentile one; by the one they went in the land of Israel, and by the other...