Day 15 concludes Chapter 10, The Teacher of the Dharma, and opens Chapter 11, Beholding the Stūpa of Treasures.

Having last month considered the tale of the thirsty man, we consider how one should expound the sutra.

“Medicine-King! The Bodhisattvas who, having been surprised at hearing this Sūtra of the Lotus Flower of the Wonderful Dharma, doubt and fear it, know this, are beginners in Bodhisattvahood. The Śrāvakas who, having been surprised at hearing this sūtra, doubt and fear it, know this, are men of arrogance.

“Medicine-King! How should the good men or women who live after my extinction expound this Sūtra of the Lotus Flower of the Wonderful Dharma to the four kinds of devotees when they wish to? They should enter the room of the Tathāgata, wear the robe of the Tathāgata, sit on the seat of the Tathāgata, and then expound this sūtra to the four kinds of devotees. To enter the room of the Tathāgata means to have great compassion towards all living beings. To wear the robe of the Tathāgata means to be gentle and patient. To sit on the seat of the Tathāgata means to see the voidness of all things. They should do these [three] things and then without indolence expound this Sūtra of the Lotus Flower of the Wonderful Dharma to Bodhisattvas and the four kinds of devotees.

Consider this explanation from the Introduction to the Lotus Sutra:

[We learn in Chapter 10, The Teacher of the Dharma, that] the teacher should expound the Dharma in accordance with the three guidelines: (1) the room of the Buddha (which is having great compassion), (2) the robe of the Buddha (which is being gentle and patient), and (3) the seat of the Buddha (which is the voidness of all things). The void in the third rule refers to a mind free from all attachments. This set of three principles, with its clear-cut presentation of the Great Vehicle, is said to be the greatest doctrine of the Buddha.

Introduction to the Lotus Sutra