Imam Ali (as): Asceticism is summed up in two phrases in the Qur'an, where Allah, most High, says, "So that you may not grieve for what has escaped you, nor be exultant at what He has given you." Therefore, one who neither grieves about past losses nor is overjoyed about the possessions he is granted has perfected his asceticism from both sides. Nahj al-Balāgha