觀無量壽佛經義疏 3.235

3.235

「『善友告曰：「汝若不能念彼佛者，應稱無量壽佛。如是至心令聲不絕，具足十念稱南無阿彌陀佛。」』」心觀為念，口誦為稱。十念，謂十聲也。四、滅罪數。

"‘The good friend tells him: "If you cannot be mindful of that Buddha, you should call upon the Buddha Amitāyus. With such a sincere mind, make your voice uninterrupted, and with ten recitations complete, call out: ‘Namo’mitābhāya Buddhāya’ [Namo Amituofo]."’" Contemplating with the mind is "mindfulness" (nian); reciting with the mouth is "calling upon" (cheng). Ten recitations refers to ten vocal utterances. Fourth, the number of sins eradicated.