en_tn/isa/28/09.md

To whom will he teach knowledge, and to whom will he explain the message?

The drunk prophets and priests use a question to criticize Yahweh and the prophets who try to correct them. AT: "The drunk prophets and priests say, 'Isaiah should not be trying to teach us about Yahweh's message!'" (See: rc://en/ta/man/translate/figs-rquestion)

To those who are weaned from milk or to those just taken from the breasts?

They use another question for the same reason. AT: "We are not babies!"

For it is command upon command, command upon command; rule upon rule, rule upon rule; here a little, there a little

The people feel that Isaiah is repeating simple commands as if talking to a child.