觀無量壽佛經疏 2.4

2.4

初言證信者即有二義：一謂如是二字，即總標教主，能說之人。二謂我聞兩字，即別指阿難，能聽之人。故言如是我聞。此即雙釋二意也。

First, regarding what is called "verifying faith", there are two meanings: First, the two words "Thus [have]" generally designate the teacher of the doctrine, the person capable of speaking. Second, the two words "I heard" specifically point to Ānanda, the person capable of listening. Therefore it is said, "Thus have I heard." This doubly explains the two meanings.