Firm was my health, my day was bright. I. Watts. [Psalms xxx.] Appeared in his Psalms of David, 1719, in 6 stanzas of 4 lines, as a paraphrase of a portion of the 30th Psalm. In the Anglican Hymn Book, 1868, it is altered to "My health was firm, my day was bright." Its use in either form is not extensive.
--John Julian, Dictionary of Hymnology (1907)