'And kill them wherever you find them,' meaning: wherever you encounter them. 'And expel them from wherever they have expelled you,' meaning: from Makkah. 'And fitnah (tribulation/disbelief) is more severe than killing.' Fitnah here means: polytheism (shirk). 'And do not fight them at the Sacred Mosque until they fight you there. But if they fight you, then kill them.' Allah, the Majestic in His remembrance, commanded His Prophet (peace be upon him) not to fight them therein until they initiate the fighting; this was before he was commanded to fight them collectively.
﴿واقتلوهم حَيْثُ ثقفتموهم﴾ أَي: وَجَدْتُمُوهُمْ ﴿وَأَخْرِجُوهُمْ مِنْ حَيْثُ أخرجوكم﴾ يَعْنِي: من مَكَّة ﴿وَالْفِتْنَةُ أَشَدُّ من الْقَتْل﴾ الْفِتْنَة هَا هُنَا: الشّرك ﴿وَلا تُقَاتِلُوهُمْ عِنْدَ الْمَسْجِدِ الْحَرَامِ حَتَّى يُقَاتِلُوكُمْ فِيهِ فَإِنْ قَاتَلُوكُمْ فاقتلوهم﴾ أَمر اللَّه - جلّ ذكره - نبيه ﷺ أَلا يقاتلهم فِيهِ حَتَّى يبدءوا بِقِتَال؛ وَكَانَ هَذَا قبل أَن يُؤمر بقتالهم كَافَّة.
