‘A monk said, “In the day there is sunlight, at night there is firelight. What is ‘divine light’?”
Joshu said, “Sunlight, firelight.”‘
(The Recorded Sayings of Zen Master Joshu)
Reading this, I immediately thought of the Harmony of Difference and Equality: ‘In the light there is darkness but don’t take it as darkness/In the dark there is light but don’t see it as light.’ The monk is trying to find something special, or essential, beyond the day-to-day (or day-to-night). Joshu points out that there is nothing beyond these things. And, to take it on to what Sekito is reminding us, the absolute is not more special than the relative, but they are constantly intertwining and equally take their places in the reality of our existence, just as day and night do.