In the Myoshin-ji school of Rinzai Zen to be a head of the meditation hall (i.e. an actual Zen teacher who trains others) one is required to be unmarried and live pretty much like a monk in other countries. Just another example.
"The shike (師家) is the teacher (師) in the monastic household (家). He is the "true" shukke who has - ideally, but not necessarily - gone through all the koan of the particular monastic koan-system, and who stays permanently in monastic life leading the monastery and guiding the monks, thus also referred to as the "elder teacher in the monk's hall" (sōdō rōshi). He has received the certificate of enlightenment (inka shōmei) just as he himself can transmit this to his successor. Unless returning to lay life, or taking up a position as priest in a temple, a shike within the Myoushinji sect is not allowed to marry but must keep the strict rules of renouncement. As such he has the prestige and generally owns the respect of being a true Zen master, a living symbol of the Zen monastic tradition, the quintessence of zen virtues ideally incarnating wisdom, spirituality, strict discipline, individuality, and yet gentle social personality. He is, in a certain sense, the religious main figure."
(Jørn Borup: Japanese Rinzai Zen Buddhism: Myōshinji, a Living Religion, p. 60)
"If the Buddha-Nature is seen, there will be no seeing of a nature in any thing."
(Nirvana Sutra, T12n374p521b3; tr. Yamamoto)
"Neither cultivation nor seated meditation — this is the pure Chan of Tathagata."
(Mazu Daoyi, X1321p3b23; tr. Jinhua Jia)
"With sudden enlightenment to Tathagata Chan,
The six paramitas and myriad means are complete within that essence."
(Yongjia Xuanjue, T2014p395c14; tr. from "The Sword of Wisdom")