Sahih al-Bukhari 4516
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).
حَدَّثَنَا إِسْحَاقُ، أَخْبَرَنَا النَّضْرُ، حَدَّثَنَا شُعْبَةُ، عَنْ سُلَيْمَانَ، قَالَ سَمِعْتُ أَبَا وَائِلٍ، عَنْ حُذَيْفَةَ، ‏{‏وَأَنْفِقُوا فِي سَبِيلِ اللَّهِ وَلاَ تُلْقُوا بِأَيْدِيكُمْ إِلَى التَّهْلُكَةِ‏}‏ قَالَ نَزَلَتْ فِي النَّفَقَةِ‏.‏