139:15 My substance. This refers to the basic frame or skeleton. Note also the similar testimony in Ecclesiastes 11:5. The marvels of embryonic growth are still largely unexplained by scientists, but God knows!

139:15 curiously wrought. “Curiously wrought” means “embroidered,” a striking description of the double-helical DNA molecular program, which organizes part by part the beautiful structure of the whole infant.

139:15 lowest parts. For “lowest parts,” read “nether parts,” or “hidden parts.” God made these hidden parts, or elements, of the earth, then formed Adam’s body from this “dust of the earth” (Genesis 2:7). He created within the body of Adam and Eve the marvelous and complex ability to multiply that body, finally to generate from these lowest parts of the earth through the curiously wrought embroidery of DNA all the many billions of their descendants, including David himself.

139:16 unperfect. This “substance yet being unperfect” is one word in the Hebrew, meaning simply “embryo.” God is watching over each embryonic human being from the moment of conception. There is never a time when it is “recapitulating” its imaginary evolutionary ancestry, as the so-called “pro-choice” people seem to think. The baby is “unperfect,” not “imperfect,” until it is ready for delivery, but it is always truly human, with an eternal soul.

139:16 continuance. “In continuance” is the same as “days” in Hebrew. That is, God was overseeing the development of all the days of the life, as well as the substance of the body.

139:16 fashioned. The embryo is being “fashioned” in a way analogous to the way in which God “formed” (same word) the body of Adam from the dust of the earth (Genesis 2:7).