宋高僧傳 29.34

29.34

系曰：凡諸入滅舉其指者，蓋示其得四沙門果之數也。昔求那跋摩舉二指而滅，言已證二果歟？其次法京垂滅，屈三指。慧景反握二指，捋之還屈。今晤之伸指，豈不同諸？

The appraisal says: Whenever monks enter cessation raising their fingers, it indicates the number of the four śramaṇa fruits they have attained. In the past, Guṇavarman raised two fingers upon cessation, saying that he had realized the second fruit. Next, Fajing, on the verge of cessation, bent three fingers. Huijing held two fingers reversed, and when straightened, they bent back again. Now, is not Wu’s extending of his hand similar to these?