Imam Husayn [a] said: "Verily, people are the slaves of the world and their religion is superficial, only on their tongues. They are attentive to it as long as their material benefits are provided, but when they are tested, the number of true devotees dwindles."
Tuhaful-'Uqul & Bihar-ul-Anwar, vol. 44, p. 374
Imam Hassan ibn Ali [a] said: "I wonder about the person who contemplates about his nutrition but he does not consider (the food of) his intellect. Thus, he avoids of what hurts him in his stomach but he lets his mind to be filled with what destroys him."
Safinat-ul-Bihar, vol. 2, p. 84
Greed and Futile Hopes
Imam Amir ul Mu'mineen Ali [a] said: "Even though miserliness, cowardice and greed are different qualities, yet they are common in having an incorrect idea about Allah."
Nahjul-Balagha, letter 52
Imam Sadiq [a] said: "If a son of Adam possessed two vast valleys wherein gold and silver flowed, he would still wish to search for the third one."
Man La Yahduruhul Faqih, vol. 4, p. 418
Imam Sadiq [a] said: "He who devotes his heart to this world will be subjected to three conditions: endless grief, unquenchable desire, and futile hope."
Usul-I-Kafi, vol. 2 p. 320
Imam Amir ul Mu'mineen Ali [a] said: "How many wretched people there are whose days are being numbered but yet they are laboriously seeking wealth."
Ghurar-ul-Hikam, p. 240