大方廣佛華嚴經疏 35.18

35.18

第三「佛子」下結成增上者，此有三義：一遍護十善，即不闕義；二常無間，即清淨義，誤犯之垢不起間故；三常無斷，即常護義。具斯三義，得增上戒名。

Third, from 'Disciples of the Buddha' below, concluding with the superior [morality] has three meanings: 1. universally guarding the ten wholesome [deeds], which is the meaning of non-deficiency; 2. constant uninterruptedness, which is the meaning of purity, because the defilement of accidental transgression does not arise to interrupt it; 3. constant ceaselessness, which is the meaning of constant guarding. Possessing these three meanings, it obtains the name 'superior morality' (adhiśīla).