Mishkat al-Masabih 19 Jihad كتاب الجهاد 5

وَعَنْ سَهْلِ بْنِ سَعْدٍ قَالَ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «رِبَاطُ يَوْمٍ فِي سَبِيلِ اللَّهِ خَيْرٌ مِنَ الدُّنْيَا وَمَا عَلَيْهَا»

Sahl b. Sa’d reported God’s Messenger as saying, “Being stationed on the frontier in God’s path for a day is better than the world and what is on it.” (Bukhari and Muslim.)