When he took so long in giving a positive response to the caliph's letter...

When he took so long in giving a positive response to the caliph's letter, 'Uthman wrote to the people of ash-Sham themselves, asking them to leave their city and hasten to his aid.(130) al-Baladhuri writes: When 'Uthman wrote to Mu'awiyah asking for his help, Mu'awiyah sent Yazid ibn Asad al-Qasri with a group of soldiers towards Medina, but ordered that on-their arrival at Dhu Khushub (131) they should set…