For shikantaza or koan zen, that says it all, imv. There’s a perfect circle hidden in the swirl of views.
The line is from the Suramgamasamadhisutra: The Concentration of Heroic Progress, p. 176. I pulled this sutra off the bookshelf after it came up in our Dogen study group.
Sometimes translated as the Heroic March Samadhi Sutra, it is regarded as a meditation manual and has been highly valued in the Zen/Chan tradition.