“The Messenger of Allah (salallahu alayhi wa sallam) said: Indifference towards this world does not mean forbidding what is permitted, or squandering wealth, rather indifference towards this world means not thinking that what you have in your hand is more reliable than what is in Allah’s Hand, and it means feeling that the reward for a calamity that befalls you is greater than that which the calamity makes you miss out on.”
— Sunan Ibn Majah, Zuhd Book 37, Hadith 4239