Flowing like the sweet-running river it evokes, a meandering metaphor for Hector’s strength and movement, likened to a thoroughbred horse breaking free and seeking out its remembered watering spots and pastures.  Other riverine triologisms include: ‘deep-running river’, ‘deep-whirling river’, and ‘deep-eddying river’. 

See also the bestellar reviews, complete with rich quote-mosaics, of Adam Nicolson’s magnificent Why Homer Matters, and Christopher Logue’s War Music, a muscular rendition of several books of the Iliad. 

‘He spoke, and breathed huge strength into the shepherd of the people.

As when some stalled horse who has been corn-fed at the manger

breaking free of his rope gallops over the plain in thunder

to his accustomed bathing place in a sweet-running river

and in the pride of his strength holds high his head and the mane floats

over his shoulders; sure of his glorious strength, the quick knees

carry him to the loved places and the pasture of horses;

so Hektor moving rapidly his feet and knees went

onward, stirring the horsemen when he heard the god’s voice speak.’

Source: Homer, The Iliad of Homer, trans. Richmond Lattimore (Chicago: Chicago UP, 1961 (1951)), book XV, p. 316