district in Gansu during the Tang dynasty
鄯 is a rare kanji that refers to a specific historical district in Gansu during the Tang dynasty. Its meaning is a proper place name with no broader conceptual center.
鄯 combines 善 (good, virtuous) with the mound/city radical ⻏, likely forming a place name. The exact historical development is uncertain.
The left side 善 suggests something good, and the right side ⻏ is a city wall. Picture a virtuous district surrounded by walls: the good place called 鄯.
For セン, imagine a thousand (千, せん) good deeds being done in this district: 千 -> セン, and the virtuous place 鄯 is filled with them.