‘Methought I Saw My Late Espousèd Saint’, sometimes known as ‘On His Deceased Wife’, is one of John Milton’s best-known sonnets. It’s a moving account of grief in the face of the loss of a loved one, and Milton – better known for his religious epic poem Paradise Lost – manages to say a great deal in just 14 lines. Before we offer an analysis of the poem, here’s a reminder of the text of ‘Methought I Saw My Late Espousèd Saint’, which was composed in 1658.
Methought I saw my late espousèd saint
Brought to me, like Alcestis, from the grave,
Whom Jove’s great son to her glad husband gave,
Rescu’d from death by force, though pale and faint.
Mine, as whom wash’d from spot of child-bed taint
Purification in the old Law did save,
And such as yet once more I trust to have
Full sight of her in Heaven without restraint,
Came vested all in white, pure as her mind;
Her face was veil’d, yet to my fancied sight
Love, sweetness, goodness, in her person shin’d
So clear as in no face with more delight.
But Oh! as to embrace me she inclin’d,
I wak’d, she fled, and day brought back my night.
Note: sometimes the opening line is rendered as ‘Methought I Saw My Late Espousèd Saint’, sometimes simply – without the accent over the final ‘e’ – as ‘‘Methought I Saw My Late Espoused Saint’. The key thing to bear in mind is that ‘espoused’ should be pronounced as three syllables – ‘es-pow-zed’ – rather than two.
‘Methought I Saw My Late Espousèd Saint’ is about the death of Milton’s second wife, Katherine Woodcock (born 1628), who died in February 1658, not long before what would have been her thirtieth birthday. To add to the tragedy, she had given birth to their child in October 1657, four months before she died; the child died six weeks after Katherine’s death.
Although paraphrase can risk destroying the beauty of a poem, it can also help us to clarify what the poet means. So, by way of summary, 
here’s a paraphrase of Milton’s meaning: Milton tells us that he thought he saw the woman he had lately married [‘espoused’], who was saintly in her goodness and is now in heaven. She appeared to him like Alcestis, the princess in Greek myth who loved her husband (Admetus), and who even died in his place. According to legend, Heracles (‘Jove’s great son’) brought Alcestis back from Hades and she was younger and more beautiful than ever.
Milton then goes on to tell us that his wife appeared to him spotless, as though she had been washed clean in accordance with ‘the old Law’, the ceremony which purified women after they had given birth (see Leviticus 12). Of course, Katherine had died not long after giving birth to her and Milton’s child. She looked exactly as Milton hopes she will look when they meet again in heaven after he has died and joined her there.
She was dressed all in white, symbolising her purity and spotlessness, and was as pure in her appearance as she was in her mind. Her face was veiled, but even though her face was concealed from him, Milton could see her love for him, her sweetness and goodness, because they shone through the veil to him.
However, as soon as she leaned towards him to embrace him, Milton woke up and realised that his vision of her had been only a dream. She disappeared, and with the arrival of day, Milton’s inner ‘night’ of darkness and grief returned.
The poem is an example of a Petrarchan or Italian sonnet, comprising an octave (eight-line section) and sestet (six-line section). The octave is rhymed abbaabba and the sestet is rhymed cdcdcd. In a Petrarchan sonnet there is typically a ‘turn’ – what is also, after the Italian term, sometimes called a volta – as the octave gives way to the sestet and the poet’s thoughts or argument change direction.
With just four different rhymes used across the fourteen lines of the sonnet, Milton’s Petrarchan sonnet is already restricted. But look how he brings the rhymes in even closer in that sestet, employing the same long ‘i’ assonance across all six words: mind, sight, shin’d, delight, inclin’d, night. We might compare such an effect with that of Sir Philip Sidney’s earlier sonnet which is also focused on blindness and sight, light and night, and similarly employs these ‘i’ rhymes (indeed, Sidney uses them across the whole sonnet, not just the sestet).
What’s so clever here, of course, is that the final line of the poem inverts the idea of day and night: night had been a time of bright shining visions of the poet’s lost beloved, whereas the (literally bright) day plunges him back into his own metaphorical night of gloom. We’ve all woken up one morning and felt depressed to discover that what we’ve just experienced was only a dream our sleeping mind conjured into existence, and now we’re awake we’re hurled back into the humdrum reality of our daily lives. But losing one’s wife and then dreaming she had returned to you, only to wake and realise she in fact remains lost from you, takes this feeling to a different level of despair and loss.
That last word, ‘night’, may also serve to remind us that for Milton, day was a continual ‘night’ in a more than metaphorical sense: around six years before he wrote ‘Methought I Saw My Late Espousèd Saint’, he had written a sonnet on his blindness, lamenting the fact that his ‘light is spent’. This sonnet about his wife’s death is not only one of Milton’s most accomplished sonnets, but perhaps his most moving. The poem shows real technical skill, but clearly springs from genuine grief following his wife’s death.