Sahih Bukhari
Prophetic Commentary on the Quran (Tafseer of the Prophet (PBUH))
Volume: 006 / Book Number: 060 / Hadith Number: 41
Narrated Abu Wail:
Hudhaifa said, "The Verse:--
"And spend (of your wealth) in the Cause of Allah and do not throw yourselves in destruction," (2.195) was revealed concerning spending in Allah's Cause (i.e. Jihad)."