It is like a grain of mustard seed, which, when it is sown upon the earth, though it be less than all the seeds that are upon the earth,

It is like a mustard seed, which is the smallest of all seeds sown upon the earth.

As a grain of mustard, which, whenever it may be sown on the earth, is less than any of the seeds that are on the earth;

As to a grain of mustard [seed], which, when it is sown upon the earth, is less than all seeds which are upon the earth,