In Matthew 13:31-32, Jesus tells the Parable of the Mustard Seed (NIV):
He told them another parable: "The kingdom of heaven is like a mustard seed, which a man took and planted in his field. Though it is the smallest of all seeds, yet when it grows, it is the largest of garden plants and becomes a tree, so that the birds come and perch in its branches."
Obviously one of the points of the parable is that while the mustard seed has a small beginning, it ends with a surprisingly large effect. This matches the theme of the immediately following Parable of the Yeast.
However, in the Mustard Seed parable Jesus also mentions that birds come and perch in the tree's branches. A couple commentators, drawing on images of birds in Ezekiel, seem to see an allegory to the Gentile inclusion. Others insist that this is strictly a one-point parable and that the birds carry no additional allegorical meaning. But recently I heard it suggested there might be a connection to the birds in the Parable of the Sower just a little before this passage:
As he was scattering the seed, some fell along the path, and the birds came and ate it up.
Beyond only the verbal connection, I don't know how such a connection is supposed to work, though. Is anyone aware of interpreters who follow such a line of thought, and if so, how does it work? And finally, is there any weight to it? Or should we see a reference to Gentile inclusion here? Or are the birds just there to aid with the visual of a big plant from a small seed?