كعب

Core meaning

The point of articulation where two segments of the body meet and take their movement.

Uses

1. ٱلْكَعْبَيْن → "knees" : the joint that bounds the washing of the legs.

   • «وَأَرْجُلَكُمْ إِلَى ٱلْكَعْبَيْنِ» — "and your feet up to the knees" (5:6)

2. كَوَاعِب → "full of vitality" : the vigour of the joints, said of companions.

   • «وَكَوَاعِبَ أَتْرَابًۭا» — "and companions full of vitality, fertile and of shared stock" (78:33)

Evidence from the text

In 5:6, the dual bounds the part of the limb to be washed by a joint, as "to the elbows" bounds the hands: it is the knee that joins the leg to the thigh. The washing stops there because, when kneeling, the leg touches the ground up to the knee, as the forearm does up to the elbow in prostration. In 78:33, the plural qualifies companions: what is said is the vigour of movement, beside أَتْرَاب, "fertile and of shared stock". The same root names ٱلْكَعْبَة, the central point of the Inviolable House.

Distinctions

• رجل — the foot, washed up to this point

See also

ترب (fertile and of shared stock, named with كواعب)