佛說盂蘭盆經疏 2.45

2.45

三藏云：「縱汝感天靈于上界、激地祇于下方，縱攝邪魔、橫羅外道，統六合以同一家、總八部以為一眾，併其神力亦不奈何。」外道道士者，外道中之道士也，簡內道中之道士。佛教初傳此方，呼僧為道士故。四天王者，毘沙門等護持世界者也。

The Tripiṭaka Master says: 'Even if you move the heavenly spirits of the upper realms and stir the earthly deities of the lower regions, even if you draw in demonic spirits and broadly gather non-Buddhists, unifying the six directions as a single family and combining the eight classes of beings as one assembly, uniting their spiritual powers would still be of no avail.' 'Non-Buddhist religious masters' means religious masters among the non-Buddhists, distinguished from religious masters within the Buddhist path. When Buddhism was first transmitted to this land, monks were called religious masters (daoshi). The 'Four Heavenly Kings' are Vaiśravaṇa and the others who protect and maintain the world.