Medb and Menstruation in the Tain Bo Cuiligne, a translation

The following excerpt from the Táin Bó Cuiligne is about an incident towards the end of the cattle raid, where Medb and her troops are retreating. Medb's menstraul period begins and she has to stop to relieve herself; while doing this Cu Chulain comes upon her and will not attack her, because of the vulnerable position she is in. Because he spares her she asks that he grant her a favor, by