Zǔtáng jí 祖堂集, fascicle 18, entry of Zhàozhōu Cóngshěn 趙州從諗: 「師問座主：「所業什摩？」對云：「講《維摩經》。」師云：「維摩還有祖父也無？」對云：「有。」師云：「阿那是維摩祖父？」對云：「則某甲便是。」」 (Sūn, Kinugawa, and Nishiguchi 2007, 785; CBETA 2021.Q4, B25, no. 144, p. 630a11–13). ( The master (i.e., Cóngshěn) asked the prelate: "What is your occupation?" [The prelate] replied: "I am lecturing on the Vimalakīrti sūtra." The master said: "Does Vimalakīrti have a grandfather?" He replied: "He has." The master said: "Which [one] is Vimalakīrtiʼs grandfather?" [The prelate] replied: "I am the one!" )

In their edition of the Zǔtáng jí 祖堂集, Sūn, Kinugawa, and Nishiguchi indicate that it is possible that in the excerpt above, the character 箇 or 個 was erroneously omitted (Sūn, Kinugawa, and Nishiguchi 2007, 785, n. 3). However, Zhān Xùzuǒ 詹緖左 has demonstrated convincingly that 阿那 is frequently used as an interrogative word in adnominal position (see Zhān 2018, 230–31).

References:

Anderl, Christoph. 2004. Studies in the Language of Zu-Tang Ji. Oslo:  Unipub. vol. 2 Acta Humaniora 213.

Sūn, Chāngwǔ, Yoshio Nishiguchi,  Kenji Kinugawa, eds. 2007. Zǔtáng jí. Beijing:  Zhōnghuá shūjú. vol. 2

Zhān, Xùzuǒ 詹緖左. 2018. Chánjí cíyǔ yánjiū: yǐ ‘Zǔtáng jí’ wéi zhǔyào kǎochá duìxiàng 禪籍詞語研究: 以’祖堂集’為主要考察對象 . Běijīng:  Kēxué chūbǎnshè.