Hadithcore
Mishkat al-Masabih, 3791

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.)

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

References1 variant
In-Book Reference
Book 19, Hadith 5