Sakkhi Sutta. A monk who does not know, for a fact, what things partake of failure, of stability, distinction and penetration, and is not strenuous, zealous, or helpful such a one is incapable (abhabba) of any achievement. A.iii.426. 

Dictionary of Pali Proper Names, G P Malalasekera (1899-1973), which is available as printed version from