How do we explain the Battle of Ullais and the mass executions done by Khalid Ibn Al-Waleed? I heard that he made an oath that if victorious, he would run the river with the blood of the enemy rather than just taking regular prisoners of war, killing 70,000

Ustadh AbdulAziz al-Haqqan

Is it authentic, alot of history reports are not authentic so make sure first.