I heard the Messenger of Allah ﷺ say, "A single day spent guarding the frontier in the cause of Allah is better than a thousand days spent in any other dwelling."
أخبرنا عمرو بن منصور قال حدثنا عبد الله بن يوسف قال حدثنا الليث عن زهرة بن معبد قال حدثني أبو صالح مولى عثمان قال سمعت
سمعت رسول الله ﷺ يقول رباط يوم في سبيل الله خير من ألف يوم فيما سواه من المنازل
[Its chain of transmission is sahih. Tirmidhi narrated it in Fadail al-Jihad, Bab ma jaa fi fadl al-murabit, no. 1667, from the hadith of Layth bin Saad, with this wording, and he said, hasan sahih gharib. It is also in al-Kubra, no. 4377. Ibn Hibban, Hakim (2/28, 13), and Dhahabi graded it sahih. See the following hadith.]