Call Jehovah thy salvation. J. Montgomery. [Psalms xci.] The manuscript of this version of Psalms xci. is not preserved with the Montgomery Manuscript. The paraphrase first appeared in Montgomery's Songs of Zion, 1822; in 5 stanzas of 8 lines, and again in his Original Hymns, 1853, No. 145. As a hymn for congregational use it is generally given in an abbreviated form, both in the older and in modern collections, as in Kennedy, 1863; the Wesleyan Hymn Book, 1875; and others. Original text as above. In America it has attained to a good position, and is sometimes found as, "Call the Lord, thy sure salvation." From this hymn also, the hymn, "God shall charge His angel legions," is taken. It is composed of stanzas iv. and v., and was given in the American Prayer Book Collection, 1826, and later hymn-books.
--John Julian, Dictionary of Hymnology (1907)