Sheikh Uthaymeen: When a person increases in luxuriousness, his greatest concern is to [indulge] his body in luxuriousness- a body whose final state will be worms and rot. It is as if the human being was not created for a great purpose- the enjoyable things of the dunya are only a means[of fulfilling needs]
Ibn Taymiyyah said: It is befitting that a person utilises wealth in the manner he utilises his donkey for riding [i.e. when he needs it].
Source: Sharh Riyaadus Saaliheen Cassette number 17