Then a third time, when the night was far advanced, at the end of the third watch, as dawn was approaching and the face of the night was beaming, Ven. Ananda arose from his seat, arranged his robe over one shoulder, stood facing the Blessed One with his hands placed palm-to-palm over his heart, and said to him: "The night, lord, is far advanced. The third watch has ended. Dawn is approaching and the face of the night is beaming. The community of monks has been sitting here long. Let the Blessed One recite the Patimokkha to the community of monks."
"Ananda, the gathering isn't pure."
Then the thought occurred to Ven. Maha Moggallana: "In reference to which individual did the Blessed One just now say, 'Ananda, the gathering isn't pure'?" So he directed his mind, encompassing with his awareness the awareness of the entire community of monks. He saw that individual — unprincipled, evil, unclean and suspect in his undertakings, hidden in his actions, not a contemplative though claiming to be one, not leading the holy life though claiming to do so, inwardly rotten, oozing with desire, filthy by nature — sitting in the midst of the community of monks. On seeing him, he got up, went over to that individual, and on reaching him said, "Get up, my friend. You have been seen by the Blessed One. You have no communion with the community of monks." Then the individual remained silent. A second time... A third time, Ven. Maha Moggallana said, "Get up, my friend. You have been seen by the Blessed One. You have no communion with the community of monks." And for a third time the individual remained silent.
Then Ven. Maha Moggallana, grabbing that individual by the arm, having expelled him through the outside door of the porch and locking the bolt, approached the Blessed One and on arrival said, "I have expelled that individual, lord. The gathering is now pure. Let the Blessed One recite the Patimokkha to the community of monks."
"Isn't it amazing, Moggallana. Isn't it astounding, how that individual waited until he was grabbed by the arm." Then the Blessed One addressed the monks: "From now on I will no longer perform the observance or recite the Patimokkha. You alone, monks, will perform the observance and recite the Patimokkha. It is impossible, it cannot happen, that a Tathagata would perform the observance or recite the Patimokkha with an impure gathering.
In reguards to this sutta, is there a commentary or explanation of what was so evil about this individual monk?