Remembering Buddha

The Pure Land teaching began with the World Honored One Shakyamuni Buddha, and has been disseminated through the generations of sage worthies.
They have divided the one gate of buddha-remembrance into four types: buddha-remembrance through reciting the name [of Amitabha Buddha], buddha-remembrance through contemplating the image [of Amitabha Buddha], buddha-remembrance through contemplating the concept [of Buddha], and reality-aspect (real mark) buddha-remembrance.
Though there are differences among the four types, ultimately they all go back to reality-aspect buddha-remembrance. Moreover, the first three types can be grouped as two: contemplating the concept, and reciting the name. [Buddha-remembrance through] contemplating the concept is explained in detail in the Sixteen Contemplations Sutra (Meditation Sutra).Here I will discuss reciting the name. The Amitabha Sutrasays:

If a person recites the name of Amitabha Buddha singlemindedly for [a period of from] one or two up to seven days without allowing anything to confuse the mind, at the end of that person’s life Amitabha Buddha and a multitude of holy ones will appear before him. As the person dies, his mind will not be deluded, and he will attain rebirth in Amitabha Buddha’s land of ultimate bliss.

This is the great [scriptural] source from which for myriad generations has come [the practice of] buddha-remembrance by reciting the name, the wondrous teaching personally communicated from the golden mouth [of Buddha]. An ancient worthy said:

As they contemplate the subtleties of the inner truth of phenomena, the minds of sentient beings are mixed [with other concerns than truth]. Since they practice contemplation with mixed minds, the contemplative state of mind is hard to achieve. The Great Sage [Buddha] took pity on them, and encouraged them to concentrate on the recitation of the buddha-name. Because it is easy to invoke the buddha-name, there starts to be some continuity [to their buddha-remembrance].

This teaches that the work of buddha-remembrance through reciting the name is most essential for being born in the Pure Land. If by reciting the name one arrives at the reality-aspect, then this has the same efficacy as subtle contemplation. Beings of the highest caliber must not doubt this.
All you children of Buddha here today, [I tell you this]: in the gate of repentance, everyone must repent — even the sages of the vehicles of the disciples [sravakas] and the solitary [pratyeka] buddhas, even the great beings of complete mind [bodhisattvas], even those of enlightenment equal to the buddhas, all must still repent. Since they all must equally repent, don’t they all have to be born in the Pure Land? How much the more so for those at the stage of ordinary mortals and those in the stages of study!
To all of you here today, disciples and others, whatever plane of existence you are in, I respectfully offer [this teaching] to you: all of you must wholeheartedly invoke the buddha-name, and seek birth in the Pure Land. I hope that Buddha’s compassion will extend down specially to you, and gather you in and save you.