The sparrow is a small bird that cannot live in the forest, but instead seeks out cracks in walls for its home, where it does not need to fear the traps of its enemies. Sparrows are very fast fliers.

The reed sparrow (passer arundineus) is born from the adulterous union of the nightingale and the sparrow. It sings more than a sparrow and less than a nightingale; it has a different song from the nightingale that is just as good. It builds a nest in the clumps of reeds and by remaining in them, gained its name.

As the sparrow rejoices to find a safe home in the cracks of walls, so does the soul rejoice when it knows that it has a home in the kingdom of heaven.