He was the preceptor (upajjhāya) of Vangīsa, and together they lived in Aggālava cetiya (S.i.185), where Kappa died. When Vangīsa questioned the Buddha as to the destiny of Kappa, the Buddha's answer was that he had completely passed away (Thag.vs.1263ff.; SN.vs.343ff). It is said (ThagA.ii.211; SNA.i.346) that Vangīsa was away when Kappa died, and had also seen him sleeping with his hands curled up. This was unlike a khīnāsava, but, in Kappa's case, it was due to long continued habit. Vangīsa, not knowing this, was assailed with doubts as to his teacher's attainments. Kappa was a vihāragaruka that is, he attached importance to keeping to his cell. When he came back from his alms rounds, he would enter his cell and not leave it again until evening or the next day. This caused disaffection in Vangīsa’s heart, which the latter quelled by force of reasoning (S.i.186; SA.i.208).
In Nigrodhakappa, Kappa was the thera's personal name, but the prefix Nigrodha was given because he attained arahantship at the foot of a nigrodha (banyan) tree. SNA.i.346; because he dwelt under a banyan, says SA.i.207.