﴿ وَقَدْ خَلَقَكُمْ أَطْوَارًا ﴾

“seeing that He has created [every one of] you in successive stages?”

when verily He created you in stages? atwār is the plural of tūr which means a state. Thus the sperm-drop is one state the blood clot is another state and so on until the creation of the human being is complete reflecting on the manner of his creation necessarily leads to belief in his Creator.