And glow more intense than blaze of branch, or brazier, Stirs the dumb spirit: no wind, but pentecostal fire In the dark time of the year. Between melting and freezing The soul's sap quivers.

-Eliot,T(homas) S(tearns)
  Four Quartets,'Little Gidding', pt.1.

Siehe, wir lieben nicht, wie die Blumen, aus einem einzigen Jahr; uns steigt, wo wir lieben, unvordenklicher Saft in dieArme. No, we don't accomplish our love in a single year as the flowers do; an immemorial sap flows up through our arms when we love.

-Rilke, Rainer Maria
  Duinieser Elegien, no.3 (translated by Stephen Mitchell in The Selected Poetry of Rainer Maria Rilke,1989).