The twenty-first path joins Chesed, Mercy, to Netzach, Victory, descending the right-hand Pillar of Mercy from the sphere of loving-kindness to the sphere of the emotions and desire. It carries the letter Kaph, whose name means "palm of the hand", the open hand that grasps, gives and receives, and by extension the turning grip of fortune.
In the Sefer Yetzirah Kaph is one of the seven double letters assigned to the seven planets, and it is given to Jupiter, the greater benefic, the planet of expansion, abundance and good fortune, an attribution that suits both the path descending from merciful Chesed and the letter's image of the hand that bestows. The seven doubles in the Sefer Yetzirah also govern seven pairs of opposites, among them wealth and poverty, the alternation of fortune, so the association of Kaph with the turning of the wheel is present already in the ancient Jewish source.