Matthew 13:51 - Ellicott's Commentary On The Whole Bible

Have ye understood all these things? — The verb is the same as that used in the parable of the Sower. An intellectual apprehension of the truth, which is also spiritual, is the condition of the growth in wisdom which enables the disciple to become in due course a teacher. There was doubtless in the answer of the disciples a grateful consciousness of a rapid increase in knowledge and insight. There was also a certain child-like naïveté in the readiness with which they declared their conviction that they had mastered all the mysteries of the kingdom which had been veiled beneath the symbolism of these earthly similitudes.