Grief rarely says when it will leave, and Bowles's sonnet begins from that uncertainty. The speaker turns to Time as one might turn to a nurse or physician. Time lays "a lenient hand" on "sorrow's wound" and, without fuss, "stealest unperceived away" the pain. The central idea is that the only cure for deep sorrow is the passing of time itself. That is a comfort, but also a hard sentence, because the sufferer has to live through the waiting. The final couplet, "Yet ah! how much must this poor heart endure, / Which hopes from thee, and thee alone, a cure!", admits as much.
The first four lines show how carefully the sonnet is built. The sentence holds back its main verb until the fourth line, so the "faint pang" is not removed until the syntax has crept toward it, which suits a healing that is "slow." The soft sibilants ("Softest on sorrow's wound," "slowly," "sense," "stealest") hush the line the way the lulling it describes would. Line three is a parenthesis, a quiet aside tucked between brackets. Even the relief it describes is "sad repose," so what Time offers is numbness and rest rather than joy. There is also a neat reversal here. Time is usually the thief who takes youth and beauty, but here it takes only the pain.
The poem never names what has been lost. The tears flow "in vain o'er all my soul held dear," and the past tense of "held" suggests, as an inference, that the loved thing is gone. The vagueness helps, since any reader's own sorrow can fill the space. The hope is also hedged at every turn. Time is the "only hope at last," which can mean both "eventually" and "when nothing else remains," and the speaker says "when thou hast dried" and "I *may* look back." He does not say "I shall."
The sonnet's finest stroke is the bird. Having imagined meeting "life's peaceful evening with a smile," the speaker compares himself to "some lone bird, at day's departing hour," singing in the last sunbeam, "of the transient shower / Forgetful, though its wings are wet the while." The image works on several levels. The day stands for a whole life, so relief arrives only at its close. The bird is "lone," as the speaker is. And the final clause undercuts the "forgetful" song, because the wings are still wet. The bird sings, but the rain has not left it. The dash after "while" leaves that damp fact hanging. Calling the shower "transient" is also something only the future self could say, since for the one still drenched in it the grief feels permanent. So the simile promises peace while quietly admitting that the peace will be partial.
The rhyme scheme (abba cddc effe gg) mixes two traditions. The enclosed rhymes of the first twelve lines, such as "lay" and "away" wrapping "thence" and "sense," give a sense of being held or bandaged, and the whole stretch from line five to line twelve runs on as a single long sentence, one extended act of hoping. Then the ending arrives as a Shakespearean-style couplet, indented on the page, and everything turns on "Yet ah!" It is the only place where the rhymes sit side by side, and what they join is "endure" and "cure." The sound ties the two words together, and the sense gives the wry point: the cure cannot be separated from the enduring. The repeated "thee, and thee alone" sounds trusting and trapped at once.
Mostly regular iambic pentameter carries all this in plain, speakable English. The old-fashioned address ("know'st," "stealest," "O TIME!") is a convention of the sonnet and does not hide the feeling. The poem matters less for novelty than for its honesty about consolation. Many poems of comfort claim that sorrow will lift. This one hopes it will and leaves the hope unfinished, with the wings still wet, the evening still far off, and the heart still enduring. That unsettled hope gives a small poem its lasting truth.