Theophylact of Ohrid

When they returned from the tomb and told the apostles about this, they were regarded as dreamers. So, by nature, the miracle of the resurrection seems incredible to people!

Commentary on Luke ↗

Augustine of Hippo

The women came to the tomb, but they didn't find the body in the tomb. Instead, they were told by angels that Christ had risen. The women reported this to men. And what's written? What did you hear? These things seemed in their eyes like an idle tale. How very unhappy is the human condition! When Eve related what the serpent had said, she was listened to straightaway. A lying woman was believed, and so we all died. But [the disciples] didn't believe women telling the truth so that we might live. …

Sermon 232.2 ↗

Bede

And these words appeared to them as an idle tale, and they did not believe them. That the disciples were slow to believe in the Lord's resurrection was not so much their weakness as our (so to speak) future firmness. For the resurrection itself was shown to them with many proofs while they doubted. As we acknowledge these things by reading, what else are we but strengthened by their doubt?

On the Gospel of Luke ↗

Bonaventure

Secondly, as regards the sight of the disciples, it is added: And these words seemed before them as idle talk, and they did not believe them. Hence they did not believe what they heard, both because what was being said was wondrous, and because this was being brought about by divine dispensation, so that a greater and more certain assertion of the truth might be obtained. Hence Gregory: "That the disciples were slow to believe was not so much their incredulity as our future firmness, so to speak. …

Commentary on Luke, Chapter 24 ↗