Divine decree versus human free will
Nahj al-Balāgha|Volume 1|Book 3|Chapter 78
٧٨. وَ مِنْ كَلَامٍ لَهُ (عليه السلام) لِلسَّائِلِ الشَّامِيِّ لَمَّا سَأَلَهُ أَ كَانَ مَسِيرُنَا إِلَى الشَّامِ بِقَضَاءٍ مِنَ اللَّهِ وَ قَدَرٍ بَعْدَ كَلَامٍ طَوِيلٍ هَذَا مُخْتَارُهُ:
78. A Syrian enquired from Amīr al-mu’minīn: Was our going to fight against the Syrians destined by Allāh? Amīr al-mu’minīn, peace be upon him, gave a detailed reply, a selection from which is hereunder: