The original cell divided, and the new cells continued to divide. Soon the cells began to differentiate, or specialize, to become nerve cells, muscle cells, skin cells, and so forth.
‏ « لَمْ تَخْفَ عَنْكَ عِظَامِي حِينَ صُنِعْتُ فِي ٱلْخَفَاءِ ،‏ حِينَ نُسِجْتُ فِي أَسَافِلِ ٱلْأَرْضِ » .‏ ‏