MARROW

A soft and fatty vascular tissue that fills the interior cavities of most bones. There are two kinds of marrow, yellow and red. In adults, the long, rounder bones are filled with yellow or inactive marrow composed mainly of fat, and the flat bones of the skull, the ribs, the sternum and the pelvis contain red or active marrow. Red marrow plays an important role in the formation of blood. It yields the oxygen-carrying red blood corpuscles, the important clotting agents called platelets, and a large percentage of white corpuscles, which primarily serve as fighters of infection. As a blood-forming organ, the marrow has a direct effect upon an individual’s health and vigor. Hence, Job (21:24) appropriately alludes to a well-nourished and healthy person under the figure of one whose bone marrow “is being kept moist.”

Bone marrow was apparently used for food by the Israelites. (Compare Micah 3:2, 3.) It has a very high nutritional value, being rich in protein, fats and iron. The banquet prepared by Jehovah for all the peoples, therefore, fittingly includes symbolic “well-oiled dishes filled with marrow.”—Isa. 25:6.

The writer of the letter to the Hebrews compared the “word of God” to a weapon that is sharper than any two-edged sword and can penetrate the very motives of an individual, piercing, as it were, clear to the marrow, the innermost part of the bones.—Heb. 4:12.