I think "the neighbouring height" referred to is the height of White Moss Common, behind the Fir-Grove, where Wordsworth was often heard murmuring out his verses," booing" as the country folks said: and the
'driving full in view
At midday when the sun was shining bright,'
aptly describes his habits as recorded in his sister's Journal, and elsewhere. The "withered flower," the "creature pale and wan," are significant of those terrible reactions of spirit, which followed his joyous hours of insight and inspiration. Stanzas IV. to VII. of Resolution and Independence (p. 314), in which Wordsworth undoubtedly described himself, may be compared with stanza III. of this poem. The lines
'Down would he sit; and without strength or power
Look at the common grass from hour to hour,'
are aptly illustrated by such passages in his sister's Journal, as the following, of 29th April 1802:
"We went to John's Grove, sate a while at first; afterwards William lay, and I lay in the trench, under the fence—he with his eyes closed, and listening to the waterfalls and the birds. There was no one waterfall above another—it was a kind of water in the air—the voice of the air. We were unseen by one another."
Again, April 23rd,
"Coleridge and I pushed on before. We left William sitting on the stones, feasting with silence."
And this recalls the first verse of Expostulation and Reply, written at Alfoxden in 1798;
Why, William, on that old grey stone,
Thus for the length of half a day,
Why, William, sit you thus alone,
And dream your time away?'