The Bodhisatta was once an ascetic in the Himavā. Near his walk lived a mongoose and a snake who were always quarrelling. He taught them the virtues of amity and dispelled their suspicions of each other.
The story was related to two of Pasenadi’s officers, who were always quarrelling. For details see the Uraga Jātaka (No.154). The two noblemen are identified with the two animals. J.ii.52 f.