Allaah (The Most High) said:

وَنَزَّلۡنَا عَلَيۡكَ ٱلۡكِتَـٰبَ تِبۡيَـٰنً۬ا لِّكُلِّ شَىۡءٍ۬

And We have revealed to you the Book (O Muhammad), as a clarification and explanation for every single matter. [16:89]

There is no such thing which mankind is in need of in their life and livelihood except that Allaah has explained it in His Book whether it is by the text (itself), or by an indication, or by something made explicit or something which is understood from the text (but is not in the text. [1]

[1] http://www.spubs.com/sps/sp.cfm?subsecID=BDH02&articleID=BDH020003&pfriend=