Obligation holy war with property in the cause of Allah

AL-BAQARA (THE COW) : 243-252

2:243. Didst thou not Turn by vision to those who abandoned their homes, though they were thousands (In number), for fear of death? Allah said to them: "Die": Then He restored them to life. For Allah is full of bounty to mankind, but Most of them are ungrateful.

2:244. Then fight in the cause of Allah, and know that Allah Heareth and knoweth all things.
2:245. Who is he that will loan to Allah a beautiful loan, which Allah will double unto his credit and multiply many times? It is Allah that giveth (you) Want or plenty, and to Him shall be your return.
2:246. Hast thou not Turned thy vision to the Chiefs of the Children of Israel after (the time of) Moses? they said to a prophet (That was) among them: "Appoint for us a king, that we May fight in the cause of Allah." He said: "Is it not possible, if ye were commanded to fight, that that ye will not fight?" They said: "How could we refuse to fight in the cause of Allah, seeing that we were turned out of our homes and our families?" but when they were commanded to fight, they turned back, except a small band among them. But Allah Has full knowledge of those who do wrong.

2:247. Their Prophet said to them: "Allah hath appointed Talut as king over you." They said: "How can he exercise authority over us when we are better fitted than he to exercise authority, and he is not even gifted, with wealth in abundance?" He said: "Allah hath Chosen him above you, and hath gifted him abundantly with knowledge and bodily prowess: Allah Granteth His authority to whom He pleaseth. Allah careth for all, and He knoweth all things."

2:248. And (further) their Prophet said to them: "A Sign of his authority is that there shall come to you the Ark of the covenant, with (an assurance) therein of security from your Lord, and the relics left by the family of Moses and the family of Aaron, carried by angels. In this is a symbol for you if ye indeed have faith."
2:249. When Talut set forth with the armies, he said: "Allah will test you at the stream: if any drinks of its water, He goes not with my army: Only those who taste not of it go with me: A mere sip out of the hand is excused." but they all drank of it, except a few. When they crossed the river,- He and the faithful ones with him,- they said: "This day We cannot cope with Goliath and his forces." but those who were convinced that they must meet Allah, said: "How oft, by Allah's will, Hath a small force vanquished a big one? Allah is with those who steadfastly persevere."

2:250. When they advanced to meet Goliath and his forces, they prayed: "Our Lord! Pour out constancy on us and make our steps firm: Help us against those that reject faith."
2:251. By Allah's will they routed them; and David slew Goliath; and Allah gave him power and wisdom and taught him whatever (else) He willed. And did not Allah Check one set of people by means of another, the earth would indeed be full of mischief: But Allah is full of bounty to all the worlds.

2:252. These are the Signs of Allah: we rehearse them to thee in truth: verily Thou art one of the messengers.

APROPOS PROPHETS AND POWER OF ALLAH