The three (sources of) felicity: (1) The 無量壽經 has the felicity of (a) 世福 filial piety, regard for elders, keeping the ten commandments; (b) 戒福 of keeping the other commandments; (c) 行福 of resolve on complete bodhi and the pursuit of the Buddha-way. (2) The 倶舍論 18, has the blessedness of (a) 施類福 almsgiving, in evoking resultant wealth; (b) 戒類福 observance of the 性戒 (against killing, stealing, adultery, lying) and the 遮戒 (against alcohol, etc.), in obtaining a happy lot in the heavens; (c) 修類福 observance of meditation in obtaining final escape from the mortal round. Cf. 三種淨業.

指往生極樂淨土者所修之三種淨業；此為過去、現在、未來三世諸佛之淨業正因。即：(一)世福，又作世善。為世俗本來存在之孝悌忠信等善法，如孝養父母、奉事師長、慈心不殺、修十善業等。(二)戒福，又作戒善。為佛出世所定之戒法，包括人、天、聲聞、菩薩所受持之三歸、五戒乃至具足眾戒，不犯威儀等。其中，或具受或不具受；或具持或不具持，但皆迴向，必能往生。(三)行福，又作行善。為凡夫起大乘心，自行化他所具之善根，即發大菩提心、深信因果、讀誦大乘經典（開智慧、厭苦欣涅槃）、勸進行者（勸人捨惡，向涅槃道）、發願往生淨土等。〔觀無量壽佛經疏（智顗）、觀經散善義、觀經序分義、觀無量壽佛經義疏卷中（元照）〕

三種的福業，即世福、戒福、行福。世福是孝養父母，奉事師長；戒福是受持三皈五戒乃至具足戒；行福是發菩提心，修行佛道。