Surprisingly, AI search has identified exact excerpts that I need from the teachings of famous Chinese Zen monks. I searched for a phrase in the records of Jìtán Zōnglè, who lived during the late Yuan and early Ming dynasties (1318–1391). 

I first tried Kyoto University's database, where it was difficult to find the specific title. However, the AI search found the exact same excerpt from the original anthology of Zen records published in China. 

Mixed Japanese script—specifically the use of kana and kanji—remains a significant obstacle for various AI models handling classical texts.

The phrase that I need is originated from Chapter 29 of 'Lǐjì' or Book of Rites, and Zen monks often refer to its 'kǒng zǐ xián jū piān' or 'Confucius at home at leisure' in their records. Anyway, it's nice to step forward for my investigation.