Hadithcore
Mishkat al-Masabih, 3831

Uthman reported God’s Messenger as saying, “A day on the frontier in God’s path is better than a thousand days in any other place." Tirmidhi and Nasa’i transmitted it.

وَعَنْ عُثْمَانَ رَضِيَ اللَّهُ عَنْهُ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ: «رِبَاطُ يَوْمٍ فِي سَبِيلِ اللَّهِ خَيْرٌ مِنْ أَلْفِ يَوْمٍ فِيمَا سِوَاهُ مِنَ الْمَنَازِلِ» . رَوَاهُ التِّرْمِذِيُّ وَالنَّسَائِيّ

References1 variant
In-Book Reference
Book 19, Hadith 43