There’s the sangha that made a vow of silence in Kd 4, the chapter on the pavāraṇā ceremony. The Buddha criticized them and said they were behaving like sheep:
Abiding in discomfort
At one time the Buddha was staying at Sāvatthī in the Jeta Grove, Anāthapiṇḍika’s Monastery. At that time in a certain monastery in the Kosalan country a number of monks who were friends had entered rainy-season residence together. They thought, “How can we remain united and in harmony, have a comfortable rains residence, and get almsfood without trouble?” Then it occurred to them, “Let’s not talk to each other. Whoever returns first from almsround in the village should prepare the seats and set out a foot-stool, a foot-scraper, and water for washing the feet. He should clean the bowl for leftovers and set it out, and put out drinking water and water for washing. Whoever returns last from almsround may eat whatever is leftover, or he should discard it where there are no cultivated plants or in water without life. He should put away the seats and also the foot-stool, the foot-scraper, and the water for washing the feet. He should clean the bowl for leftovers and put it away, put away the drinking water and the water for washing, and sweep the dining hall. Whoever sees that the pot for drinking water, the pot for washing water, or the waterpot in the restroom is empty should fill it. If he can’t do it by himself, he should call someone over by hand-signal and they should fill it together. He should not speak because of that. In this way we’ll remain united and in harmony, have a comfortable rains residence, and get almsfood without trouble.” And they did just that. Now it was the custom for monks who had completed the rains residence to go to see the Buddha. So when the rains residence was over and the three months had elapsed, those monks put their dwellings in order, took their bowls and robes, and left for Sāvatthī. When they eventually arrived at Sāvatthī, they went to the Jeta Grove, Anāthapiṇḍika’s Monastery. There they approached the Buddha, bowed, and sat down. Since it is the custom for Buddhas to greet newly arrived monks, the Buddha said to them, “I hope you’re keeping well, monks, I hope you’re comfortable; I hope you spent the rains at ease, in concord and harmony, without dispute, and that you had no trouble getting almsfood?” “We’re keeping well, Venerable Sir, we’re comfortable; we spent the rains at ease, in concord and harmony, without dispute, and we had no trouble getting almsfood.” When Buddhas know what is going on, sometimes they ask and sometimes not; they know the right time to ask and the right time not to ask. Buddhas ask when it is beneficial, not when it is unbeneficial; Buddhas have destroyed access to what is unbeneficial. Buddhas question the monks for two reasons: to give a teaching or to lay down a training rule. And the Buddha said to those monks, “In what way, monks, did you spend the rains at ease, without having any trouble getting almsfood?” When they had told him, the Buddha addressed the monks: “While they dwelt in discomfort these foolish men claim they were dwelling at ease. While they dwelt together like animals, they claim they were dwelling at ease. While they dwelt together like sheep, they claim they were dwelling at ease. While they dwelt together like enemies, they claim they were dwelling at ease. How can these foolish men take a vow of silence, as do the ascetics of other sects? This won’t give rise to confidence in those without it …” … after rebuking them and giving a teaching, he addressed the monks: “You should not take a vow of silence, as do the ascetics of other sects. If you do, you commit an offense of wrong conduct.
