Qualities to keep the heart open: Be as patient as the moss and as vulnerable as the oaks. 

Isn’t it plain the sheets of moss, except that
they have no tongues, could lecture
all day if they wanted about

spiritual patience? Isn’t it clear
the black oaks along the path are standing
as though they were the most fragile of flowers?

Every morning I walk like this around
the pond, thinking: if the doors of my heart
ever close, I am as good as dead.

Mary Oliver, Landscape (extract)