“That's it!”

When, earlier in his ministry as a famous Zen roshi, Takuan was asked by a monk whether he ever performed the sacred Nembutsu recitation of the holy Name of Amida Buddha, he replied, “No, never.” “Why not?” “Because I don’t want my mouth polluted!” Yet it's funny: Takuan had spent years in his youth involved in chanting Amida's name as a member of the Pure Land devotional Buddhist sect!

Later, in his little text Reiroshu, Takuan told the following story:

When Ippen Shonin (13th cent.; later a father of Pure Land Buddhism) met Zen master Hotto Kokushi, the founder of the Kokokuji Temple in Yura village, he said, “I have composed a poem.” Master Kokushi said, “Let's hear it.” Shonin recited: 
When I chant,
Both Buddha and self
Cease to exist,
There is only the voice that says,
Namu Amida Butsu.

Kokushi said, “Something's wrong with the last couple of lines, don't you think?” Shonin then confined himself in Kumano and meditated for twenty-one days. When he passed by Yura again, he said to the Master, “This is how I've written it”:
When I chant,
Both Buddha and self
Cease to exist.
Namu Amida Butsu,
Namu Amida Butsu.

Kokushi nodded his enthusiastic approval, “That's it!”