Ibn 'Umar said, "The Messenger of Allah, may Allah bless him and grant him peace, took hold of my shoulders and said, "Be in this world as if you were a stranger or a traveller on the road." Ibn 'Umar used to say, 'In the evening, do not anticipate the morning, and in the morning do not anticipate the evening. Take from your health for your illness and from your life for your death."

Riyadh-as-Saliheen by Imam Al-Nawawi, volume 3, hadith number 471 - Sunni Hadith