大方廣佛華嚴經隨疏演義鈔 17.71

17.71

“At that time the Elder Ānanda, single-mindedly joining his palms toward the direction of the Buddha's nirvāṇa, spoke thus: ‘When the Buddha first preached the Dharma, at that time I did not see it; I heard it thus through transmission. When the Buddha was in Vārāṇasī, for the five bhikṣus the Buddha first opened the gate of ambrosia and taught the Dharma of the four noble truths: the truths of suffering, origination, cessation, and path. Ājñātakauṇḍinya first attained the vision of the path, and eighty thousand devas, hearing this, attained the vision of the path.’” Through passages such as these, it is clear that this was transmitted hearing, hence it says “or heard through transmission.”