Ezekiel 3:5

a strange speech lit. deep of lip(or speech) and heavy of tongue. The former expression perhaps refers to the inarticulateness with which, to one unacquainted with their language, foreigners appear to speak; and the other to the thickness of their utterance. The first half of the expression occurs again Isaiah 33:19, a people of deep speech, so that thou canst not perceive; and the second half is said of Moses, Exodus 4:10.