The importance of understanding (fiqh)

يَـٰٓأَيُّهَا ٱلنَّبِىُّ حَرِّضِ ٱلْمُؤْمِنِينَ عَلَى ٱلْقِتَالِ ۚ إِن يَكُن مِّنكُمْ عِشْرُونَ صَـٰبِرُونَ يَغْلِبُوا۟ مِا۟ئَتَيْنِ ۚ وَإِن يَكُن مِّنكُم مِّا۟ئَةٌ يَغْلِبُوٓا۟ أَلْفًا مِّنَ ٱلَّذِينَ كَفَرُوا۟ بِأَنَّهُمْ قَوْمٌ لَّا يَفْقَهُونَ

O Prophet, urge the believers to battle. If there are among you twenty [who are] steadfast, they will overcome two hundred. And if there are among you one hundred [who are steadfast], they will overcome a thousand of those who have disbelieved because they are a people who do not understand.