The Coccyx

 The Messenger of Allaah, sallallaahu ‘alayhi wa sallam, said,

“The ground will consume all of the body of the son of Aadam except the coccyx: from it he was formed and in it he will be rebuilt.”

(Al-Bukhaari,, Muslim, An-Nasaa‘i, Abu Daawood, Ibn Maajah, Ahmad and Maalik]

Scientific Analysis

Modern embryology has clarified that the 'Ajb ath-thanab [translated above as “coccyx”] is the primitive streak.

According to embryologists, the coccyx (tailbone) is the small bone associated with the section at the bottom of the spine, usually consisting of four fused vertebrae. It is considered to be the foundation of the primitive streak, which precedes the formation of the fetus, most notably its nervous system. After the primitive streak disappears, the coccyx is all that remains.

The development of the primitive streak is an indication that the organs and tissues of the fetus are being formed. In fact, the stage known as organogenesis does not start until the formation of the primitive streak, the neural groove, and the somites. This continues from the beginning of the fourth week to the end of the eighth week. At the end of this stage, the fetus is equipped with all its basic systems and its organs are formed, followed only by tiny details and bodily growth.

Having fulfilled its purpose in the fourth week, the primitive streak starts to shrink, leaving some traces in the sacrococcygeal region, remaining unseen to the naked eye.

The Miracle

The narration about the coccyx is a miracle of the Prophet, sallallaahu ‘alayhi wa sallam. He basically explained modern embryology, confirming that mankind is something composed and that he originates in the coccyx (or what is called the “primitive streak”). This is where cells are prompted to divide, to take on special roles, and to be distinguished from each other.

Directly after its appearance, the nervous system begins to form; first is the neural groove, then the neural tube, and then the rest of the nervous system. This is the foundation upon which the remaining organs are based. The primitive streak then begins to vanish, leaving but a trace in the sacrococcygeal region, in which the coccyx is formed and from which we will be recompiled on the Day of Resurrection.

“The ground will consume all of the body of the son of Aadam except the coccyx: from it he was formed and in it he will be rebuilt.”