All my words, etc. The stress lies on the first word. The prophet was not to pick and choose out of the message, but was to deliver "all the counsel of God" (Acts 20:27). Take into thine heart, etc. An inverted order of the two commands would, perhaps, have seemed more natural.
What we actually find, however, is sufficiently suggestive. The message of Jehovah is first received into the inner depths of the soul, but in that stage it is vague, undefined, incommunicable. It needs to be clothed in articulate speech before it can be heard with the mental ear and passed on to others.
The mouth speaks out of the fulness of the heart.