俱舍論記 4.53

4.53

「此中信者至故名為信」者，信謂令心澄淨，理亦能令心所淨，從強說心。由此信珠在心皆得澄淨，故《入阿毘達摩》解信云「是能除遣心濁穢法，如水清珠置於池內，令濁穢水皆即澄淨。如是信珠在心池內，心諸濁穢皆即除遣（已上論文）。」有說：此信於四諦、三寶、善惡業、異熟果中現前忍許，故名為信。又《正理》云「為欲所依，能資勝解（解云：由信彼故，希求彼境。信許有境，方能印可。此明信因）。」

"Here, faith means... therefore it is called faith": faith means making the mind clear and pure; in principle, it can also make the mental factors pure, but one speaks of the mind because it is predominant. Because of this jewel of faith being in the mind, all become clear and pure; hence the Abhidharmāvatāra explains faith: "It is a factor capable of dispelling turbidity and defilement of the mind, like a water-clearing jewel placed in a pond, which makes the turbid and defiled water immediately clear and pure. Just so, when the jewel of faith is within the pond of the mind, all turbid defilements of the mind are immediately dispelled (this ends the treatise text)." Some say: this faith is the present assent and confidence regarding the four noble truths, the three jewels, wholesome and unwholesome karma, and ripened effects; therefore it is called faith. Furthermore, the Nyāyānusāra states: "It is the support for desire, and can foster determination (the explanation says: because of having faith in that, one aspires toward that object. Only when one has faith in and assents to the object can one approve it. This clarifies the cause of faith)."