(5) باب الْغَدْوَةِ وَالرَّوْحَةِ فِي سَبِيلِ اللَّهِ، وَقَابُ قَوْسِ أَحَدِكُمْ مِنَ الْجَنَّةِ
Narrated Anas bin Malik:
The Prophet (ﷺ) said, "A single endeavor (of fighting) in Allah's Cause in the forenoon or in the afternoon is better than the world and whatever is in it."
Reference: Sahih al-Bukhari 2792
In-book reference: Book 56, Hadith 10
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 52, Hadith 50