1. Ājañña Sutta.-Like a king's thoroughbred horse possessed of beauty, strength, speed and good proportions, a monk worthy of offerings should have beauty (of life), strength (of character), speed (of insight) and good proportions (of necessaries). A.ii.250-1.
2. Ājañña Sutta.-Same as above, but speed of insight in a monk is depicted as ability to enter into the four jhānas. A.ii.251-2.
3. Ājañña Sutta.-On eight qualities that a horse should possess in order to be worthy of being used by the king, and on eight similar qualities essential in the ideal monk. A.iv.188ff.