Vishwamitra and the Gayatri mantra

Vishwamitra and the Gayatri Mantra.  A King sees Vasistha’s magic cow but can’t steal it.  He retires to the forest and becomes the rishi Vishwamitra and eventually becomes a Brahamrishi and cognizes the Gayatri Mantra.  Chanting of Gayatri mantra and Agni Suktam from Rig Veda.