For the earth brings forth fruit of itself; first the blade, then the ear, after that the full grain in the ear.
All Commentaries on Mark 4:28 Go To Mark 4
Gregory The Dialogist
AD 604
To produce “the blade” is to hold the first tender beginning of good. The “blade” arrives at maturity when virtue conceived in the mind leads to advancement in good works. The “full corn” fructifies in “the ear” when virtue makes such great progress that it comes into its fullest possible expression.