法苑珠林 23.57

23.57

佛告太子。菩薩世世至誠不欺。是故得好高聲如梵天聲。由世世不惡口。是故得八種音。由世世不兩舌不妄語。是故眾人所念悉皆能報。

The Buddha told the prince: 'Because the bodhisattva generation after generation is utmostly sincere and does not deceive, he obtains an excellent, lofty voice like the voice of Brahmā. Because generation after generation he does not use harsh speech, he obtains the eight kinds of vocal qualities. Because generation after generation he is free from double-tongued speech and false speech, he is fully able to respond to whatever thoughts the multitude has.'