We can never predict the power of our actions. The word said, the deed done, disappear into the past, but often, years later, we can be astounded to learn of their impact. A friend explodes with rage over an imagined slight; a stranger thanks us for a favor we’d forgotten. In this poem, Longfellow compares two forms of action, represented by an arrow and a song. The speaker shoots an arrow into the air and it falls to earth, out of sight.