MY glaſſe ſhall not perſwade me I am ould,
So long as youth and thou are of one date,
But when in thee times forrwes I behould, ſorrowes/forrowes?
Then look I death my daies ſhould expiate.
For all that beauty that doth couer thee,
Is but the ſeemely rayment of my heart,
Which in thy breſt doth liue, as thine in me,
How can I then be elder than thou art?
O therefore loue be of thy ſelfe ſo wary,
As I not for my ſelfe, but for thee will,
Bearing thy heart which I will keepe ſo chary
As tender nurſe her babe from faring ill,
Preſume not on thy heart when mine is ſlaine,
Thou gau’ſt me thine not to giue backe againe.
Sonnet 22 differs from Sonnet 3, where the youth is instructed to gaze upon himself in a mirror; here the poet uses his glass to argue about age and its effects. He will not be persuaded, looking at himself in the mirror, that he is old, as long as the friend retains his youth: as long as the youth and youthfulness have the same terminal date (“one date” as in a lease or contract) or cease at the same time. On the other hand, when the time comes that he sees furrows on the youth’s brow (“times forrwes,” to be preferred to “times sorrowes”), then he will contemplate the fact (“look”) that he must pay his debt to death (“death my daies should expiate”); to “expiate” or ‘extinguish what is owed’ was linked with death (see R3 3.3.23, “the houre of death is expiate”). The youth’s outer beauty, that which ‘covers’ him, is but a proper garment (“seemely raiment”) dressing the poet’s heart. His heart thus lives in the youth’s breast as the youth’s heart lives in his: the hearts being one, no difference of age is possible (“How can I then be elder then thou art?”).
The poet admonishes the youth to be cautious about himself (“of thy selfe so wary”), just as the poet will be, not for his own sake but for the youth’s (“As I not for my selfe, but for thee will”). He will carry about the youth’s heart (“Bearing thy heart”) and protect (“keepe”) it; “chary” is an adverbial usage and means ‘carefully.’ His chariness will be like a solicitous (“tender”) nurse preventing her ward from faring ill. The couplet is cautionary and conventional: when the poet’s heart is slain, then the youth should not take for granted (“presume”) that his heart, dressed in the poet’s, will be restored to him. It was not given as something to be returned or as a debt needing expiating: “Thou gau’st me thine not to giue backe againe.”