"A slave(muslim) will not be able to take a step further on the Day of Requital until he is taken to account for [the following things]: his time and how he spent it, his knowledge and how he used it, his money and how he earned and spent it, and his youth and how he passed it." (Tirmidhi)
Umar reported that he heard the Prophet (peace and blessings be upon him) say, "Do not wear silk, for those who wear it in this life shall not wear it in the Hereafter." (Reported by al-Bukhari and Muslim) On another occasion, referring to a silken garment, he said, "This is the dress of a man who has no character.'' (Reported by al-Bukhari and Muslim)
Ali reported that the Prophet (peace and blessings be upon him) took some silk in his right hand and some gold in his left, declaring, "These two are haram for the males among my followers."
Quran: "Righteousness is not that you turn your faces toward the east or the west, but [true] righteousness is [in] one who believes in Allah, the Last Day, the Angels, the Book, and the prophets and gives wealth, in spite of love for it, to relatives, orphans, the needy, the traveler, those who ask [for help], and for freeing slaves." (2:177)
Quran: "Eat and drink and do not waste, verily Allah does not love those who waste." (S:7, V:31)
Showing off, good link:
http://www.scribd.com/doc/7834332/Showing-Off-The-Hidden-Shirk
This one may answe your verse "You shall not keep your hand stingily tied to your neck, nor shall you foolishly open it up, lest you end up blamed and sorry"