Theophylact of Ohrid

At His words, "the girl is not dead, but sleeping," they laugh; this was permitted so that afterward they would have no pretext to say that she had been in a faint and that it was no wonder if He raised her. On the contrary, they would convict themselves by their own testimony of His raising one who was truly dead, since they had even laughed at His words that she was not dead but sleeping.

Commentary on Mark ↗

Augustine of Hippo

He comes to the house, and finds the customary funeral rites already underway, and he says to them, "Why do you make a tumult and weep? The child is not dead, but sleeping." He spoke the truth. She was in a certain sense asleep—asleep, that is, in respect of him, by whom she could be awakened. So awakening her, he restored her alive to her parents.

Sermon On New Testament Lessons 48 ↗

Ambrose of Milan

And what shall I say of the daughter of the ruler of the synagogue, at whose death multitudes were weeping and the flute-players piping? For the funeral solemnities were being performed because of the conviction of death. How quickly at the word of the Lord does the spirit return, the reviving body rise up, and food is taken, that the evidence of life may be believed!

On the Decease of His Brother Satyrus, Book 2 ↗

Bede

And entering, he said to them: Why are you troubled and weeping? The girl is not dead, but sleeping. To men she was dead, who could not raise her, but to God she was sleeping, in whose arrangement, the soul was received and lived, and the body rested to be resurrected. …

On the Gospel of Mark ↗