In Jodo Shu Buddhism, whose practice I have been more or less following for 3 weeks,* there is a lot of questions about how much one should recite the nembutsu, Amida Buddha’s name (namu amida butsu). In Honen’s time, he assigned some followers very large quotas per day of 10’s of thousands of recitations of the nembutsu. Then for other people he didn’t assign quotas, and they recited the nembutsu far, far less, but were still seen by Honen as devout followers.
Jodo Shu, like all Pure Land Buddhism in Japan, China and elsewhere, teaches that one can be born in the Pure Land very easily simply by reciting Amida’s name as little as 10 times. So, should one just recite a few times and leave it at that? Or should one keep striving their whole lives? Does endless striving betray a lack of faith in Amida Buddha’s Vow?
Honen explained the subject nicely when he said:
You should believe that you will be received into the Pure Land by even one recitation of O-Nenbutsu and yet practice O-Nenbutsu throughout your life.
It seems that yes indeed a few recitations, or even one sincere recitation will grant one rebirth in the Pure Land, but Honen’s argument is why stop there? The Contemplation of Amitabha (Amida) Sutra states:
Because he [the sentient being] calls the Buddha’s Name, with each repetition, the evil karma which he has committed during eighty kotis of kalpas of Samsara is extinguished.
And in the Larger Sutra of Immeasurable Life:
 The Buddha said to Maitreya, “If there are people who hear the Name of that Buddha, rejoice so greatly as to dance, and remember him even once, then you should know that they have gained great benefit by receiving the unsurpassed virtue. For this reason, Maitreya, even if a great fire were to fill the universe of a thousand million worlds, you should pass through it to hear this sutra, to arouse joyful faith, to uphold and chant it, and to practice in accordance with its teachings. This is because there are many bodhisattvas who wish to hear this teaching but are still unable to do so.
So, with each sincere recitation you do, nothing but good can come of it. Hence Honen is saying why stop with a few?
* – Have had a couple “short” days, but I usually try to make those up the following day, per Honen’s advice. Last night I was dead tired and just couldn’t stay awake. One has to know one’s limits, but also be diligent in keeping up the practice in the long-run.