In Andrew Marvell's poem, "To His Coy Mistress," the speaker is trying to convince a woman he desires to give in to him.
He begins with the idea that if it were possible, they could take all the time they want. She could be coy and flirtatious—no big deal. They could go their separate ways: she to the "Indian Ganges' side" to find rubies, and he to complain of Humber (where he grew up). He would love her ten years before the Flood (of Noah, in the Old Testament of the Bible), and she could continue to refuse him until the Jews were converted to Christianity. He would praise her eyes for a hundred years; each breast for two hundred years, "but thirty thousand to the rest." He would devote "an age" to every part, the last being her heart. She would deserve this and he would give her no less.
However, in the second stanza Marvell introduces the theme popular with the Cavalier poets: Carpe Diem, which literally means "seize the day," or let's live for today." Basically the speaker is saying, "time is wasting," for:
...at my back I always hear / Time's winged chariot hurrying near...
Tine is rushing up behind us; our lives are flying past. The future holds nothing but "eternity." She will lose her beauty. In her "marble vault" where they bury her his song will not be heard. The worms will do their work, and her virginity and honour will "turn to dust." And the passion he feels for her will burn itself out till nothing but ash remains. The grave is all well and good, he says, but people don't hug there.
So, he says in the third stanza, let's make the most of this moment: let's not waste time...not while your skin is young "like the morning dew," while her willing soul is pouring itself out of her pores with the fires of her passion. While we are still young, let us make the most of our time together and use all of our time to its best advantage. Let's roll strength and sweetness together and take all our pleasure as we may. We may not be able to stop the sun (time), but we can make the sun "run to keep up" with us.