Wash you, make you clean... — The words were probably as an echo of Psalms 51:7. Both psalmist and prophet had entered into the inner meaning of the outward ablutions of ritual.
Cease to do evil; (17) learn to do well. — Such words the prophet might have heard in his youth from Amos (Amos 5:14-15). What had then been spoken to the princes of the northern kingdom was now repeated to those of Judah.