The poem
Thus can my love excuse the slow offence Of my dull bearer, when from thee I speed: From where thou art, why should I haste me thence? Till I return, of posting is no need. O, what excuse will my poor beast then find When swift extremity can seem but slow? Then should I spur, though mounted on the wind; In wingèd speed no motion shall I know. Then can no horse with my desire keep pace; Therefore desire, of perfect'st love being made, Shall neigh-no dull flesh-in his fiery race. But love, for love, thus shall excuse my jade: Since from thee going he went wilful-slow, Towards thee I'll run, and give him leave to go.