A person stands at the edge of the sea before dawn and dips a hand into the water. That small, quiet action is the whole scene, but the last two lines turn it into something larger. The speaker isn't just checking the temperature. They want to learn "the difference between / air and prayer."
That odd pairing suggests a moment where the ordinary and the sacred sit very close together. Air is what we breathe without thinking, and prayer is a kind of breath too, spoken or silent, sent out toward something unseen. By touching the sea, the speaker seems to be searching for a way to feel that difference physically rather than explain it.
The mood is hushed, patient, and a little uncertain. "Not yet light" leaves everything in half-darkness, so the speaker has to rely on touch. The poem feels like a held breath, open to wonder without claiming any answer.