四分律行事鈔資持記 3.671

3.671

四中。《母論》四名，局據夏限；若如《五分》，取上無人，隨時受稱，則通大小。今時禪眾，無論老小，例稱上座，不知孰為下座乎！

In the fourth [part]. The four names in the Vinayamātṛkā are restricted to limits of summer retreats; if it is like the Mahīśāsaka-vinaya, taking the absence of anyone above oneself to receive the designation according to the time, then it applies universally to junior and senior. Nowadays in Chan assemblies, regardless of old or young, all are called sthavira (elder)—I do not know who is considered the junior!