Joseph Benson's Commentary of the Old and New Testaments - Isaiah 28:9-10
Isaiah 28:9-10. Whom shall he Namely, God, or his prophet, or minister; teach knowledge? and whom shall he make to understand doctrine? Who is there among this people, that are capable and willing to be taught the good knowledge of God? them that are wearied from the milk, &c. A minister may as soon teach a young child as these men. For precept must be upon precept, &c. They must be taught like little children, slowly, and with leisure, the same things being often repeated,... read more
Albert Barnes' Notes on the Whole Bible - Isaiah 28:10
For precept must be upon precept - This is probably designed to ridicule the concise and sententious manner of the prophets, and especially the fact that they dwelt much upon the same elementary truths of religion. In teaching children we are obliged to do it by often repeating the same simple lesson. So the profane and scoffing teachers of the people said it had been with the prophets of God. It had been precept upon precept, and line upon line, in the same way as children had been instructed.... read more