'Mustard seed' in the Bible

Another parable delivered He unto them, saying, The gospel-kingdom is like a grain of mustard-seed, which a man took and sowed in his field.

And Jesus said unto them, because of your unbelief: for verily I tell you, if ye had but faith as a grain of mustard-seed, ye might say to this mountain, Remove from hence thither, and it shall remove: and nothing would be impossible to you.

It is like to a grain of mustard-seed, which when it is sown in the ground, is one of the lest of all the seeds on the earth:

It is like a grain of mustard-seed, which a man took and sowed in his garden, and it grew, and became a great tree, and the birds of the air lodged in it's boughs.

And the Lord said, If ye had faith but as a grain of mustard-seed, ye might say to this sycamine-tree, Be thou rooted up and planted in the sea; and it would obey you.