‘All sentient beings, from beginninglessness, within the six realms, have no [negative] karma not created. If without the mind to cultivate [Dharma] practice, instead, [they] do not feel that [they] have these kinds of strange and evil thoughts. If giving rise to the aspiration to cultivate practice, thus [might] these kinds of thoughts be even more. (These attachments are truly from false perceptions and forms manifested, not that in the past they are absent, but that they were not obvious.)
At this moment, [you] should think that ‘Amituofo (Amita[bha] Buddha) is in front of me’, [thus] not daring to have one stray thought or false thinking, with utmost sincerity and earnestness mindful[ly reciting] the Buddha’s sacred name (be it with low volume reciting, or silently reciting). There must be, with word after word, and line after line, within the mind reciting that is very clear, within the mouth reciting that is very clear, with the ears listening very clearly.
Able to in this way constantly recite, thus will all stray thoughts, naturally be eliminated. When stray thoughts arise, all the more give rise to complete vigour to be mindful of Buddha[‘s name], not allowing them (stray thoughts to), within my mind create trouble. If able to in this way constantly recite, thus [will the] mind’s ground be naturally [clear and] pure.
When stray thoughts first arise, like one person with ten thousand persons as enemies, [you] must not slightly have the tolerant and undisciplined mind. If not, they [the stray thoughts] will become my master, and I will receive harm from them. If staking one’s life to counteract [with mindfulness of Buddha], they will follow me to be transformed, which is so-called to transform afflictions to bodhi [i.e. awakening].
You now, are able to, constantly with [Amita(bha)] Tathagata’s great name of ten thousand virtues’ ultimate power counteract [stray thoughts], [and] as time passes, [your] mind will naturally become [clear and] pure. With [your] mind [clear and] pure already, remain the same, with mindfulness not slackened, and thus will karmic obstacles be eliminated and wisdom awaken. Be sure not to give rise to the impatient [or irritable] mind [during practice].’
Dharma Master Yinguang’s Collected Writings: Third Compilation, Scroll 2
(First Reply to Layman Ye Fubei)