What ails my heart, that in my breast ? G. Wither. [Sleeplessness.] First published in his Haleluiah; or, Britan's Second Remembrancer. London, 1641, Pt. i., No. 20, in 4 stanzas of 8 lines. It is introduced by the following note:—
"When we cannot sleep at seasonable times, vain musings and want of right meditating on God, is frequently chief cause of unrest. Therefore this meditation directeth to the remedy of such untimely watchfulness."
The hymn is included in Fair's reprint of the Hallelujah in 1857, and thence it passed, with slight alterations, into Kennedy, 1863, No. 845. [William T. Brooke]
--John Julian, Dictionary of Hymnology (1907)