“Experience has taught me, when I am shaving of a morning, to keep watch over my thoughts, because, if a line of poetry strays into my memory, my skin bristles so that the razor ceases to act…The seat of this sensation is the pit of the stomach. Houseman's test for great poetry.”

"Manifeston On Ars Poetica," lines 1-3.
Visions and Reflections (1972)

"Firefly" on Greta Gaines (1999); the phrase in quotes is one earlier found in "Strange Fruit" (1937) by Abel Meeropol, famously sung by Billie Holiday.
Context: I wake to "magnolias sweet and fresh",
Lines of poetry on my breath,
You were here but you have stolen away.
My inspiration is an evening star,
So come to me wherever you are,
I will wait for you tonight alone in the dark…

Source: Simon and Garfunkel's Greatest Hits

A History of the Lyre
The Venetian Bracelet (1829)

Dialogues on Metaphysics (1688) Dialogue III
Context: I am unable, when I turn to myself, to recognize any of my faculties or my capacities. The inner sensation which I have of myself informs me that I am, that I think, that I will, that I have sensory awareness, that I suffer, and so on; but it provides me with no knowledge whatever of what I am — of the nature of my thought, my sensations, my passions, or my pain — or the mutual relations that obtain between all these things … I have no idea whatever of my soul.

Guo Moruo, 1983. As quoted in Yuan Li (2016), Study of Comparative Poetic Thought of Guo Moruo's Goddess [original in Chinese]
G - L

"The Autobiography of Sir William Topaz McGonagall".
Other works

The Art of Poetry - interview 1995 with Downing & Kunitz