Day 20 completes Chapter 15, The Appearance of Bodhisattvas from Underground, and concludes the Fifth Volume of the Sutra of the Lotus Flower of the Wonderful Dharma.

Having last month heard Maitreya question Śākyamuni, we now repeat in gāthās.

Thereupon Maitreya Bodhisattva, wishing to repeat what he had said, sang in gāthās:

It is not long
Since you renounced the family of the Śākyas
And sat under the Bodhi-tree
Near Gaya.

These sons of yours are innumerable.
They have practiced
The way to Buddhahood for a long time.
They have supernatural powers and the power of wisdom.

They have studied the Way of Bodhisattvas well.
They are not defiled by worldliness
Just as the lotus-flower
Is not defiled by water.

They sprang up from underground,
And are now standing before you respectfully.
This is difficult to understand.
How can we believe this?

Lotus World: An Illustrated Guide to the Gohonzon offers this on the relationship of a Lotus Flower and its muddy lifesource.

The lotus flower is rich in symbolism within Buddhism. In Nichiren Buddhism, two aspects are particularly emphasized. The first is the unification of cause and effect, the simultaneous nature of the aspiration for enlightenment and its realization. The lotus flower symbolizes this because it produces flowers and seeds at the same time. By chanting the Odaimoku, we express both the aspiration for enlightenment – the seed of awakening to the Wonderful Dharma – and also our awakened devotion to the Wonderful Dharma – the flowering of enlightenment. The second aspect is the undefiled flowering of enlightenment arising out of the defilements of ordinary life that are transformed by the power of Buddhist practice. In the same way, lotus flowers blossom untainted above the mud and water from which they draw their nourishment. Because it illustrates these two key principles, the lotus flower is a particularly important symbol for Nichiren Buddhists.Lotus World: An Illustrated Guide to the Gohonzon