Adam Clarke on Psalms 139:16

Thine eyes did see my substance - גלמי golmi, my embryo state - my yet indistinct mass, when all was wrapped up together, before it was gradually unfolded into the lineaments of man. "Some think," says Dr. Dodd, "that the allusion to embroidery is still carried on. As the embroiderer has still his work, pattern, or carton, before him, to which he always recurs; so, by a method as exact, revere all my members in continuance fashioned, i.e., from the rude embryo or mass they daily received some degree of figuration; as from the rude skeins of variously coloured silk or worsted, under the artificer's hands, there at length arises an unexpected beauty, and an accurate harmony of colcurs and proportions."

And in thy book all my members were written - "All those members lay open before God's eyes; they were discerned by him as clearly as if the plan of them had been drawn in a book, even to the least figuration of the body of the child in the womb."