'In Me' in the Bible

I will stand at my guard postAnd station myself on the tower;And I will keep watch to see what He will say to me,And what answer I will give [as His spokesman] when I am reproved.

I heard, and I trembled within me, at the voice, my lips, quivered, decay, entered, my bones, and, in my limbs, I trembled, - though I am to find rest, in the day of distress, when their invader, cometh up against the people.