Word by Word Analysis

وَلَوْ أَنَّا كَتَبْنَا عَلَيْهِمْ أَنِ ٱقْتُلُوٓا۟ أَنفُسَكُمْ أَوِ ٱخْرُجُوا۟ مِن دِيَـٰرِكُم مَّا فَعَلُوهُ إِلَّا قَلِيلٌ مِّنْهُمْ ۖ وَلَوْ أَنَّهُمْ فَعَلُوا۟ مَا يُوعَظُونَ بِهِۦ لَكَانَ خَيْرًا لَّهُمْ وَأَشَدَّ تَثْبِيتًا 66

And if We had decreed upon them, "Kill yourselves" or "Leave your homes," they would not have done it, except for a few of them. But if they had done what they were instructed, it would have been better for them and a firmer position [for them in faith].