Nahj al-Balāgha
Hadith 1867٢٩٦. وَقَالَ (عليه السلام) لِرَجُلٍ رَآهُ يَسْعَى عَلَى عَدُوٍّ لَهُ بِمَا فِيهِ إِضْرَارٌ بِنَفْسِهِ: إنَّمَا أَنْتَ كَالطَّاعِنِ نَفْسَهُ لِيَقْتُلَ رِدْفَهُ.
296. Amīr al-mu’minīn, peace be upon him, saw a man busy against his enemy with what was harmful to himself too, so he said: You are like one who pierces a spear through himself in order to kill the person sitting behind him.