Moosā was a shy person and used to cover his body completely because of his extensive shyness.
One of the children of lsrael hurt him by saying, “He covers his body in this way only because of some defect in his skin, either leprosy or scrotal hernia, or he has some defect.”
Allah wished to clear Moosā of what they said about him, so one day while Moosa was in seclusion, he took off his clothes and put them on a stone and started taking a bath.
When he had finished the bath, he moved towards his clothes so as to take them, but the stone took his clothes and fled.
Moosā picked up his stick and ran after the stone saying, “O stone! Give me my garment!” Till he reached a group of Bani Israel who saw him naked then, and found him the best of what Allah had created, and Allah cleared him of what they had accused him of…
This was what Allāh refers to in His Saying: “O you who believe! Be you not like those Who annoyed Moosā, But Allāh proved his innocence of that which they alleged, And he was honorable in Allāh’s Sight. ” (33:69)
[صحيح البخاري ٣٤.٤]