Gen sits in the northwest in the Earlier Heaven arrangement attributed to Fuxi, opposite Dui in the southeast. In the Later Heaven arrangement attributed to King Wen it moves to the northeast, the quarter the applied traditions associate with it.
The northeast in the Later Heaven order is the hinge between the end of one cycle and the start of the next, the turn from deep winter toward spring, and the Shuogua describes Gen as the place where the cycle both finishes and begins again. A trigram whose attribute is the mountain and whose name is glossed as Keeping Still belongs at that pause. The reading is not that nothing is happening there but that the stopping is what makes the next beginning possible.
In the Later Heaven order Gen belongs to the phase Earth, which it shares with Kun, and the two hold the diagonal corners of the diagram. From the Shuogua Gen takes the dog among animals, the watcher that stays at the threshold, and the hand among the parts of the body, the part that grasps and therefore also holds still. In the family scheme Gen is the youngest son, its single yang line in the top place.
Gen and Zhen are inversions of each other, one yang line at the top against one yang line at the bottom, and the tradition reads them as stopping and starting respectively.
Sources Fathoming the Cosmos and Ordering the World: The Yijing (I Ching, or Classic of Changes) and Its Evolution in ChinaRichard J. Smith with The I Ching, or Book of ChangesRichard Wilhelm (trans.); Cary F. Baynes (English trans.), The Five "Confucian" ClassicsMichael Nylan