Day 29 covers all of Chapter 25, The Universal Gate of World-Voice-Perceiver Bodhisattva.

Having last month concluded Chapter 25, we begin again at the top.

Thereupon Endless-Intent Bodhisattva rose from his seat, bare j his right shoulder, joined rus hands together towards the Buddha, and said, “World-Honored One! Why is World-Voice-Perceiver Bodhisattva called World-Voice-Perceiver?”

The Buddha said to Endless-Intent Bodhisattva:

“Good man! If many hundreds of thousands of billions of living beings hear [the name of] World-Voice-Perceiver Bodhisattva and call his name with all their hearts when they are under various sufferings, World-Voice-Perceiver Bodhisattva will immediately perceive their voices, and cause them to emancipate themselves [from the sufferings]. Those who keep the name of this World-Voice-Perceiver Bodhisattva will not be burned when they are put into a conflagration [because they are protected] by, the supernatural powers of this Bodhisattva. Those who call his name will be able to take ground when they are washed by an inundation. Suppose hundreds of thousands of billions of living beings are crossing an ocean in order to obtain gold, silver, lapis lazuli, shell, agate, coral, amber pearl, and other treasures, and suppose the ship carrying them is blown to the country of rākṣasa-devils by a storm. If one of the crew calls the name of World-Voice-Perceiver Bodhisattva, all the crew will be saved from the attacks of the rākṣasas. Because of this, [this Bodhisattva] is called World-Voice-Perceiver.

Nichiren writes in his “A Response to My Lady Nichinyo”:

The chapter “Bodhisattva Voice Perceiver” is also known as the chapter “Universal Gate.” Since the first half of this chapter tells of the merits of a person who pays homage to the Bodhisattva World Voice Perceiver (Avalokiteśvara), this chapter is named “Voice Perceiver.” It is also named “Universal Gate” since the latter half tells of the merits of a person who takes refuge with the Lotus Sutra which the Bodhisattva Voice Perceiver maintains.

Nichinyo Gozen Gohenji, A Response to My Lady Nichinyo, Writings of Nichiren Shōnin, Volume 4, Faith and Practice, Pages 133-134