Seers sacrificing on the Sarasvati drive Kavasha Ailusha from the Soma, calling him a slave woman's child, a cheat and no Brahman, and send him to the desert to die of thirst, barred from the river. Thirsting there, he sees the hymn RV 10.30. The waters well out after him and Sarasvati runs all around him, at the place called Parisaraka. The seers conclude that the gods know him, call him back and perform the hymn. It is to be recited without a break so that rain falls without a break.
Formerly Rakshasas watched the fords and killed whoever came for water; Kavasha saw the fifteen-verse hymn and by it drove them from the fords. Separately: the Madhyamas hold a session on the Sarasvati; Kavasha sits among them and they refuse to eat with the son of a slave woman. He rushes off in anger praising the Sarasvati with the hymn; she follows him. Their passion leaves them; they go after him, bow, call him the best of them and remove his anger.
What is different here:
No desert, no thirst, no wish for his death: only a refused meal. Kavasha leaves angry of his own accord, and the seers go to him. Adds the Rakshasas at the fords.
Sources: Rigveda Brahmanas: the Aitareya and Kausitaki Brahmanas, tr. A. B. Keith (1920); Hymns of the Rigveda, tr. R. T. H. Griffith (1896), hymns read for the Vedic layer