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

Having last month concluded Chapter 25, The Universal Gate of World-Voice-Perceiver Bodhisattva, we start again with the question of Endless-Intent Bodhisattva.

Thereupon Endless-Intent Bodhisattva rose from his seat, bared 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.

The Daily Dharma from May 2, 2021, offers this:

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].”

The Buddha gives this description of World-Voice-Perceiver Bodhisattva (Kuan-Yin, Kannon, Kanzeon, Avalokitesvara) to Endless-Intent Bodhisattva in Chapter Twenty-Five of the Lotus Sūtra. World-Voice-Perceiver is the embodiment of compassion, a living manifestation of the desire that all beings be happy and free from suffering. By calling the name of this Bodhisattva, we awaken the compassion within ourselves. We become this Bodhisattva and remove our fear of suffering. With this awakening we can be fully present for those in this world of conflict who are suffering and liberate ourselves from the delusion and isolation of our own suffering.