Hannan ibn Kharija reported: I said to Abdullah ibn ‘Amr, may Allah be pleased with him, “What do you say about jihad and military campaigns?” Abdullah said, “Begin with your soul and wage jihad against it. Begin with your soul and wage a military campaign against it.”
Source: Muḥāsabat al-Nafs 62
عن حَنَّان بْن خَارِجَة قَالَ قُلْتُ لِعَبْدِ اللَّهِ بْنِ عَمْرٍو رضي الله عنه كَيْفَ تَقُولُ فِي الْجِهَادِ وَالْغَزْوِ قَالَ ابْدَأْ بِنَفْسِكَ فَجَاهِدْهَا وَابْدَأْ بِنَفْسِكَ فَاغْزُهَا
62 محاسبة النفس لابن أبي الدنيا ابدأ بنفسك