大日經持誦次第儀軌 1.123

1.123

va言vaṃ大悲水臍，功德乳海所滋潤故。如水能從高赴下，多有饒益滋潤草木、華菓，本性清淨；如是，如來智水從真言法界流趣世閒，潤諸持生助道之法，成大果實，常以洗濯菩提之心，不令染污也。

Va, speech, vaṃ: the navel of great compassion water; because it is moistened by the milk-ocean of merits. Just as water can flow from high to low, bringing great benefit and moistening grass, trees, flowers, and fruits, its intrinsic nature being pure; in this way, the wisdom water of the Tathāgata flows from the mantra-dharmadhātu into the world, moistening all practices that sustain life and aid the path, bringing about great fruits, constantly washing the bodhicitta, and not allowing it to be defiled.