A.T. Robertson Commentary Mark 4:13

"And he saith unto them, Know ye not this parable? and how shall ye know all the parables?" — Mark 4:13 (ASV)

Know ye not this parable? (ουκ οιδατε την παραβολην ταυτεν; ). They had asked Jesus his reasons for using parables. This question implies surprise at their dulness though initiated into the secret of God's Kingdom. Incapacity to comprehend this parable of the sower raises doubt about all the others on this day and at all times.