[I]t is stated in the “Understanding by Faith” chapter of the Lotus Sūtra:

“We are greatly indebted to the World Honored One. Making use of various inexplicable powers, out of compassion He enlightened us, bringing benefit to us. In countless millions of kalpa (aeons) who can ever repay His great favors? Even if we offer Him our hands and feet, bow our heads respectfully and present all manner of offerings, none of us can repay His great favors. Or even if we carry Him on our heads, bear Him on both our shoulders, for kalpa as numerous as the sands in the Ganges River respect Him from bottom of our hearts; even if we offer Him delicious food, innumerable jeweled garments, together with articles of bedding, various kinds of medicines, or even if we build with ox-head sandalwood and all kinds of rare gems a stupa mausoleum and cover the ground with jeweled robes. Even if we were to do all this as the offering to the Buddha for as many kalpa as the sands of the Ganges River, still we will be unable to repay His great favor.”

This scriptural passage is the expression of gratitude of four great śrāvaka disciples to the Buddha and the Lotus Sūtra for preaching the “Parable” chapter telling them that they, too, will become Buddhas. Therefore, these śrāvaka disciples must have understood that those who practice the Lotus Sūtra are more precious than one’s own parents, loving children, two eyes, and even their own lives. It is inconceivable that such great śrāvaka disciples as Śāriputra and Maudgalyāyana would abandon those who praise any of the holy teachings preached during His lifetime. However, it is possible that they bear some resentment against the pre-Lotus sūtras. The reason being in those pre-Lotus sūtras the Two Vehicles, śrāvaka and pratyekabuddha, are strongly denied the status of Buddhahood in such phrases as, “In Buddhism, the Two Vehicles are like the rotten seeds of Buddhahood.”

Kitō Shō, Treatise on Prayers, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 58