續一切經音義 10.98

10.98

拓跋（上他各反下盤末反後魏姓也魏書云黃帝昌意少子受封於北地以土德王北人謂土為拓謂后為跋故以拓跋為氏至孝文帝因讀周易見乾卦云元者萬善之始遂改為元氏也）。

拓跋 (The first character has the fanqie 他各 [tā + gè]; the second has the fanqie 盤末 [pán + mò]; the surname of the Later Wei. The Weishu states: 'The younger son of Changyi, son of the Yellow Emperor, was enfeoffed in the northern lands and ruled through the virtue of Earth. The northern people call earth 拓 and lords 跋; hence they took Tuoba as their clan name. When it came to Emperor Xiaowen, because he read the Zhouyi and saw the Qian hexagram stating: “The primary [元] is the head of all goods,” he subsequently changed it to the Yuan [元] clan.').