That these bodhisattvas [from Underground] did not originally dwell in the earth but that they, who were in the infinite space below the sahā-world, came out of the earth and rose into the sky has a deep meaning. These bodhisattvas were people who had been freed from illusion in their previous lives by means of the Buddha’s teachings. For this reason, they had been dwelling in infinite space. But hearing the Buddha declare that he would entrust the instruction of the sahā-world to them, they entered into the earth, namely, this sahā-world, experiencing suffering there, and practiced religious disciplines so zealously as to attain the mental state of bodhisattvas. Therefore, they rose into the sky again after coming out of the earth. Though the bodhisattvas had been free from illusion in their previous lives, they voluntarily passed through various sufferings and worries in sahā-world for the purpose of saving the people here, endeavored earnestly to become enlightened, and preached the teaching to others. As mentioned before, this is a very important process; without completing such an endeavor, they could not truly acquire the divine power to save the people in the sahā-world.