Day 30 covers all of Chapter 26, Dhāraṇīs

The merits a single gāthā of four lines from the Lotus Sutra:

Thereupon Medicine-King Bodhisattva rose from his seat, bared his right shoulder, joined his hands together towards the Buddha, and said to him:

“World-Honored One! How many merits will be given to the good men or women who keep, read, recite, understand or copy the Sūtra of the Lotus Flower of the Wonderful Dharma?”

The Buddha said to him:

“Suppose some good men or women make offerings to eight hundred billion nayuta Buddhas, that is, as many Buddhas as there are sands in the River Ganges. What do you think of this? Are the merits given to them many or not?”

“Very many, World-Honored One!”

The Buddha said: “More merits will be given to the good men or women who keep, read or recite even a single gāthā of four lines of this sūtra, understand the meanings of it or act according to it.”

The vows of the 10 rākṣasīs daughters and their mother, the Mother-Of-Devils, and her children and attendants:

Anyone who does not keep our spells
But troubles the expounder of the Dharma
Shall have his head split into seven pieces
Just as the branches of the arjaka-tree [are split].

Anyone who attacks this teacher of the Dharma
Will receive the same retribution
As to be received by the person who kills his parents,
Or who makes [sesame] oil without taking out worms [from the sesame],
Or who deceives others by using wrong measures and scales,
Or by Devadatta who split the Saṃgha.

And in exchange, the Buddha promises them merits:

The Buddha said to the rākṣasīs:

“Excellent, excellent! Your merits will be immeasurable even when you protect the person who keeps only the name of the Sūtra of the Lotus Flower of the Wonderful Dharma. Needless to say, so will be your merits when you protect the person who keeps the sūtra itself, and makes to a copy of this sūtra hundreds of thousands of offerings such as flowers, incense, necklaces, powdered incense, incense applicable to the skin, incense to burn, streamers, canopies, music, and various lamps like lamps of butter oil, oil lamps, lamps of perfumed oil, lamps of sumanas-flower oil, lamps of campaka flower oil, lamps of vārṣika-flower oil, and lamps of utpala-flower oil. Kuntī! You [rākṣasīs] and your attendants should protect this teacher of the Dharma.”