Were glad (echarēsan). Second aorist passive indicative of chairō as in Mar 14:11. Ingressive aorist, a natural exultation that one of the Twelve had offered to do this thing.
Covenanted (sunethento). Second aorist indicative middle of suntithēmi. An old verb to put together and in the middle with one another. In the N.T. outside of Joh 9:22 only in Luke (here and Act 23:20; Act 24:9). Luke only mentions “money” (argurion), but not “thirty pieces” (Mat 26:15).