Oso-eko (Amida's instructions on virtue for entering the Pure Land) is one of Jodo Shinshu's (the True Pure Land Buddhist Sect) important doctrines and corresponding term to Genso-Eko (Amida's instructions on virtue for returning to this world). T'an-luan (early Chinese Pure Land philosopher and popularizer) explains Oso-eko in his main literary work "Muryoju-kyo Ubadaisha Ganshoge-chu" (also known as Ojoronchu) (Commentary on Vasubandhu's Upadesa on the Sutra of Immeasurable Life, also known as Ojoron-chu or Wangsheng lun zhu (Notes on the Treatise on Birth - in the Pure Land): Oso-eko means to give to all others one's virtues acquired through practicing good conduct and accumulating merits, and to aspire that everyone including oneself attains birth in Amida's Pure Land.
Shinran maintains that both Oso-eko and Genso-eko can only be achieved by the Other Power out of Amida's instructions and giving of virtue, and rejecting self-power where one tries to attain enlightenment by practicing good conduct and accumulating merit through one's own efforts. In conclusion, he explains that everything is fulfilled by the power of Amida's Primal Vow.
Kyogyoshinsho (Teaching, Practice, Faith, and Enlightenment)
By devoting our thinking about the true purpose of the way to the Pure Land, we can see that Amida's instructions of virtue to sentient beings have two aspects:
To go forward to the Pure Land and the return to this world. To go forward, there is the Teaching, Practice, Faith, and Enlightenment of the truth.
(From "A Collection of Passages that Reveal the True Lessons, Practice and Understanding of the Way to the Pure Land")
Each of above is explained by Shinran as follows.
To unveil the true lessons: One must study the Larger Sutra of the Buddha on Immeasurable Life. The central purpose of this sutra is that Amida, by creating the Vows, has opened the doors to the dharma-storehouse, displaying his compassion for small, lesser creatures, chooses and grants a virtuous treasure. Shakyamuni came into this world and preached the way to enlightenment, to save the multitudes of living creatures by blessing them with benefits that are truthful and genuine. So, to preach Tathagata's Primal Vow is the true intention of this sutra; the essence is in the Name of the Buddha.
Devotedly thinking about Amida's instructions on virtue for the journey to the Pure Land, there is great practice, great faith. Great practice in reciting the Name of Tathagata of prevailing light. Embodying all good acts, possessing all the roots of virtue, is the most perfect and quickest way to bring about birth. It is a treasure house of virtues that is the true reality. And because of this, it is called great practice. This practice comes from the vow of great compassion (17th Vow). It is understood as "the Vow for the name all Buddhas extol," " all Buddhas Vow to say the Name," and " all Buddhas have Vowed to praise the Name," "the Vow to instruct virtue for our journey" and "the Vow for which reciting the Name is chosen."
Unending devotion to thinking about Amida's instructions of virtue for our journey forward, there is great faith. Great faith is the way to attain longevity and immortality, the awesome way to awake aspirations for the pure and to reject the corrupt, the honest mind taught to us through this chosen Vow, the faith that realizes Amida's benefiting of others, the true mind shining like a diamond jewel that is indestructible, the pure faith whereby a person can easily find the Pure Land where no one goes, a single mind, understood by those who are embraced and protected by the compassionate light, the great faith, rare and unsurpassed, the quickest path that is difficult for people to accept, the true reason for attaining nirvana, the white path by which all virtues are instantly fulfilled and the vast sea of faith that is the true reality. Through the nenbutsu (Buddhist invocation) the mind arises from the Vow of birth. This great selected Primal Vow of the threefold mind, the Vow of sincerity and trustfulness, and may also be called the Vow of faith, which is Amida's instructions on virtue for our journey forward. For the ever sinking foolish and ignorant in birth-and-death, the multitudes caught in revolving transmigration, it is not difficult to attain of the fruit of enlightenment; the real difficulty is realizing faith in it's true and real form. The reason is because this realization comes about through Tathagata's powerful support; completely through the power of compassion and wisdom. If pure shinjin is to be realized, it is a mindset that will not be innovated; it will not be false or in vain. A sentient being of extreme evil, profound, and gigantic, will realize great joy and receive love and veneration of all the honored sacred ones.
To unveil, with steadfast devotion, the true understanding: It is a wonderful state achieved through Amida's pure benefiting of others; it is the ultimate flowering of supreme nirvana. It blooms from the Vow of the achievement required of nirvana (the 11th Vow). Also it is known as the Vow achieving great nirvana. When the foolish ones possessing blind passion, the multitudes caught in the endless birth-and-death circle defiled by evil karma, realize the mind and practice what Amida instructs them to do on their journey forward, they immediately join the truly settled of the Mahayana. Because they live among the truly settled, they attain nirvana. To attain nirvana is to achieve eternal bliss. Eternal bliss is the ultimate tranquility. Tranquility is supreme nirvana. Supreme nirvana is the eternal dharma-body. The eternal dharma-body is true reality. True reality is the nature of dharma. The nature of dharma is suchness. Suchness is oneness. Amida Tathagata emerges from suchness and is manifested in various bodies; transformed, accommodated, and fulfilled.
As can be seen from the above, how foolish beings attain birth in the Pure Land is explained through Teaching, Practice, Faith, and Enlightenment. Teaching shows how Amida came to establish the Vows, which is expounded in "Bussetsu Muryoju-kyo" (the Sutra of the Buddha of Immeasurable Life); the Vows themselves; and how everything relies on Amida's directing of virtues based on his wisdom and compassion. This does not mean practice when foolish beings direct their merit toward attaining birth, but is the practice fulfilled when Amida instructs out of great compassion. Faith is not the belief that foolish beings have in Amida, but is what is instructed to them by the power of the Primal Vow. Similarly, it is explained that Enlightenment is what is attained by Amida and is directed to living beings.
Such terms as Tariki-eko (directing of virtues by another Other Power) and Tariki-hongan (Salvation through the power of Amida's Primal Vow) have thus emerged through the conception that the Kyogyoshinsho is all brought to perfection by Amida,