Isaiah 28:23

Give ye ear, and hear my voice
So said the prophet, as the Targum introduces the words; and because what he was about to say was of importance, and delivered in a parabolical manner, and required attention, he makes use of a variety of words to the same purpose, to engage their attention:

hearken, and hear my speech;
now about to be made; listen to it, and get the understanding of it.