金剛般若經依天親菩薩論贊略釋秦本義記卷上 1.112

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經。須菩提我今實言告汝若有善男子善女人以七寶滿爾所恒河沙數三千大千世界以用布施得福多不　第三問福也。我今實言告汝者。為欲校量先顯如來口無失故。若善男子等者。兼明能之心也。以七寶者。正明所施之量也。滿爾所恒河沙數世界者。總顯施寶量也。

[Sūtra:] "'Subhūti, I now speak to you truthfully: if a good man or good woman were to fill with the seven treasures as many three-thousandfold great-thousandfold world-systems as the sands in those Gaṅgā Rivers, and use them for giving, would that person obtain much merit?'"
This is the third [part], asking about the merit. "I now speak to you truthfully" means that, wishing to make the comparison, [the Buddha] first shows that the Tathāgata's speech is free of error. "If a good man [or good woman]", etc., additionally clarifies the capacity of the mind [of the donor]. "With the seven treasures" directly clarifies the measure of what is given. "Fill as many world-systems as the sands in those Gaṅgā Rivers" comprehensively shows the quantity of the given treasures.