成唯識論了義燈 7.226

7.226

答：以於此地斷第十地自障盡已，方欲斷彼第十一障，故須加行種種修學，得經多時，故別立名。

Answer: It is because, after having completely severed the obstacles proper to the tenth ground on this ground, he only then desires to sever those obstacles of the eleventh ground; thus, he must engage in various types of cultivate-and-learn practices of the preparatory path (prayogamārga), which can take many kalpas. Therefore, a distinct name is established.