摩揭陀國迦蘭陀竹園西南，行五六里，南山之北，有大石窟，如來滅後，迦葉於此結集三藏，同時去石窟二十餘里之處，其餘大眾，結集五藏，故起窟內窟外之稱。見西域記九，宗輪論述記。
'Within the cave,' the assembly of the elder disciples, after Śākyamuni's death, in the cave near Magadha, when, according to tradition, Kāśyapa presided over the compiling of the Tripiṭaka; while at the same time the 窟外 disciples 'without the cave' compiled another canon known as the 五藏 Pañcapiṭaka. To this separation is ascribed, without evidence, the formation of the two schools of the 上座部 Mahāsthavirāḥ and 大眾部 Mahāsāṅghikaḥ.