Musannaf Ibn Abi Shayba 27:243

'Abbad ibn al-'Awwam narrated to us, from al-'Ala' ibn al-Musayyab, from a man who narrated to him, he said: The disciples said to 'Isa ibn Maryam, peace be upon him: "What do you eat?" He said: "Barley bread." They said: "And what do you wear?" He said: "Wool." They said: "And what do you use as a bed?" He said: "The earth." They said: "All of this is difficult." He said: "You will not attain the kingdom of the heavens and the earth until you endure this with pleasure," or he said: "with desire."