The speaker recounts a morning when three figures appeared to him out of the blue. He describes their dress as Grecian, and says they resembled figures on an urn because they hold hands and rotate around, as if the urn was being turned. He doesn't understand why they appeared to him this way, without telling him who they were.
He also chastised them for ruining a day of pleasant idleness. They reappeared to the speaker several times, and during one of their visits he realized that he recognized them: they are Love, who appears as a lovely young woman; Ambition, who is weak and anxious; and Poesy (a.k.a. poetry) who is a wily demon that tempts him the most.
He says that he is tempted to join them, but this temptation is only fleeting. He instead decides to stay and enjoy his idleness, which provides a numb pleasure akin to napping outside on a warm day. During their final visit, he tells the figures to leave so that he can continue napping in the grass and enjoying his laziness.