"The first line offers a major concept, in impressive phrasing. Instead of developing the concept, as a concept, however, in the manner of a poet of the Renaissance, Hopkins proceeds to illustrate it with two descriptive figures. In the first of these we are confronted with the kind of ambiguity which occurs so often in Hopkins: if we assume that the second line is grammatically correct, then foil is a quantitative word and refers to tin-foil or to gold-leaf, or to something of that nature, and we have what amounts, in effect, to an image of a mad man (or at least of a remarkably eccentric man) brandishing a metal bouquet; if the foil in question, however, is a fencing foil, then the grammar is defective, for the article is omitted.^[*] This particular defect is not an uncommon form of poetic license, especially in Hopkins, and Hopkins takes much greater liberties elsewhere; but the image is indeterminate. In the next image there is a curious inaccuracy of natural description: "crushed" (or spiolled) oil does not "gather" to a greatness, it spreads; or, if Hopkins is referring to the gathering of oil from the crushing of olives, he is not only incomplete but is again inexact in his grammar."

Yvor Winters, "Gerard Manley Hopkins," in Hopkins: A Collection of Critical Essays. Edited by Geoffrey H. Hartman. Englewood Cliffs: Prentice-Hall, 1966.  47.

* "We learn from a note on page 226 of Gardner (Poems of Gerard Manley Hopkins, third edition) that Hopkins had shaken goldfoil in mind. We do not learn how it was shaken. The ambiguity is still in the text of the poem, however, and the essential weakness of the image remains." [Winter's note.]