It is like a grain of mustard seed, which, when it is sown in the earth, is less than all the seeds that be in the earth: A grain of mustard seed - See on Matthew 13:31, Matthew 13:32 (note).
Related Commentaries of Mark 4:31
Mark 4:31
31 It is like a grain of mustard seed, which, when it is sown in the earth, is less than all the seeds that be in the earth: