And he said, How might we compare the reign of God, or in what parable shall we place it? 31 As a grain of mustard, which, whenever it is sown on the ground, being the smallest of all the seeds that are on the ground, 32 and whenever it is sown, it comes up and becomes greater than all the garden plants and makes great branches, so that under its shade the birds of the heaven are able to dwell.
Jesus’ image of a tree in which birds make their nests (cf. Matt. 13:32; Lk. 13:19) recalls passages in the Old Testament in which Babylon and Egypt are depicted as trees that provide a home for the birds of the air and shelter for the beasts of the field (Ezek. 31:6; Dan. 4:12). Conceivably Jesus meant by the parable of the mustard seed that the movement of renewal in Israel that he was initiating would become a ‘kingdom’ to rival the empires of the world, providing an alternative form of security and prosperity. In Ezekiel 17:22-24 the image appears to be used for Israel replanted following exile.