'Grain' in the Bible

At that time, Jesus went on the Sabbath day through the grain fields. His disciples were hungry and began to pluck heads of grain and to eat.

He set another parable before them, saying, "The Kingdom of Heaven is like a grain of mustard seed, which a man took, and sowed in his field;

He said to them, "Because of your unbelief. For most certainly I tell you, if you have faith as a grain of mustard seed, you will tell this mountain, 'Move from here to there,' and it will move; and nothing will be impossible for you.