Commentary Par XI 51

The Ganges, about which we will hear again in [Par XIX 71], was for Dante the defining eastern limit of his world.  (Seville [[Inf XX 126] and [Inf XXVI 110]] was close to the western limit, as Ulysses discovered).  For earlier reference to the Ganges, see [Purg II 5] and [Purg XXVII 4].