Therein (en tautēi). That is, “in faith,” feminine demonstrative referring to pistis.
The elders (hoi presbuteroi). More nearly like “the fathers,” not the technical sense of elders (officers) usual in the N.T., but more like “the tradition of the elders” (Mar 7:3, Mar 7:5; Mat 15:2).
Had witness borne to them (emarturēthēsan). First aorist passive of martureō (cf. Heb 7:8), “were testified to.”