Very interesting verses. In Nahjul Balagha Imam Ali (as) says that in a battlefield Prophet (saww) used to send his own family members of Bani Hashim to fight out the battle at the front. Imam Ali (as) too in the battles of Jamal, Siffein, Naharwan had his sons Mohammad ibn al Hannafiya, and Abbas leading the people. This was so nobody could ever get a chance to doubt the truthfulness and sincerity of their mission.