The Holy Prophet (S) said: "At the moment when the coffin of a person is being lifted and carried, the concerning soul follows its corpse and regretfully calls: 'O you my children and my relatives! Beware that the world does not cheat you as it did me. I gathered wealth regardless of it being lawful or unlawful and left all of it for others. Now I am left with its burden upon me while they enjoy the fruit of it; therefore, avoid that which is similar to what happened to me'."
Bihar-ul-Anwar, vol. 6, p. 161
Imam Amir ul Mu'mineen ‘Ali (‘a) said: "If man perceived his death and its speed towards him, he would certainly detest the world and its hopes."
Bihar-ul-Anwar, vol. 73, p. 166
Imam al-Kadhim, the seventh Imam (‘a), said: "The likeness of this world is as a snake which is soft to the touch while there is killing poison in its inside. Possessors of wisdom avoid it but children (naive ones) are fond of it and like to catch it with their hands."
Bihar-ul-Anwar, vol. 78, p. 311
Imam as-Sadiq (‘a) said: "The love of this fleeting world is the origin of all vices."
Al-Kafi, vol. 2, p. 315