Teach me, my God and King. G. Herbert. [Duty.] This hymn is found in modern hymnbooks in two forms, the first as written by Herbert, and the second as altered by J. Wesley. Herbert's text was printed in his Temple, 1633, p. 178, under the title "The Elixir"; and J. Wesley's in his Collection of Psalms & Hymns, 1738.
In modern hymnbooks, as in Mercer and others, J. Wesley's text, with the omission of the last stanza, is usually followed. We must note that in Herbert's text the line (a) reads in the 7th ed. "Which with this tincture for Thy sake," and that in later editions of J. Wesley's Collection of Psalms & Hymns the following changes are also made :—
(b) "Nothing so small can be."
(c) "Hallow'd is toil, if this the cause."
(d) "The elixir this the stone."
This rugged, but beautiful hymn is we! adapted in its original form for private use.
-- Excerpts from John Julian, Dictionary of Hymnology (1907)