Imam Ahmad b. Hanbal said, “Zuhd is of three levels. The first is abstaining from the unlawful, and this is the zuhd of the common folk. The second is to abstain from the lawful things that are beyond one’s need, and this is the zuhd of the elite. The third is to abstain from that which distracts one from Allah, and this is the zuhd of the sages.”
[Madaarij al-Salikin]