Matthew Poole and continuators on Deuteronomy 4:11

11 And ye came near, and stood under the mountain, and the mountain burnt with fire unto the midst of heaven , with darkness, clouds and thick darkness.

Flaming up into the air, which is oft called Heaven, and the midst or the heart of it is not onely that which is strictly and properly the middle part, but that which is within it, though but a little way, in which sense places or persons or things are said to be in the heart of the Sea, Exod. 15. 8. Prov. 23. 34. Ezek. 28. 2. and Christ in the heart of the Earth. Matth. 12. 40.

Marginal references: Exod. 19. 18.; Heb. heart.