On the authority of Abdullah ibn Umar (May Allah be pleased with them both), he relates that the Prophet (Peace be upon him) once held my shoulders and said:

"Live in this world as (if you are) a wayfarer or a stranger." And Abdullah ibn Umar (May Allah be pleased with them both) used to say: "If you live till night, then do not wait for the next day (i.e. do not have hopes that you will live to the next day), and if you wake up in the morning do not have hope that you will live till the night. And take (advantage) from your health before your sickness and take advantage of your life before your death (i.e. do every possible obedience in your life before death comes to you for then no deeds can be performed.)"

[Bukhari and Tirmidhi]

Explanation

The similitude of 'Living in this world as a wayfarer' is like that of a traveler in this world who undertakes a journey and then stops to rest under the shade of a tree in a particular place. So the traveler ties his mount, lays down his luggage and retires for a moment under the shade in the midday heat, reclining against the tree. Then after having rested a while, he gathers his belongings, unties his mount and resumes his journey moving away from the temporary resting place, where he had sheltered for a short time. Such is the similitude of man in this world, who resides in this temporary abode of the world for a short time, and then he must thereafter continue his journey towards his real destination, which is the hereafter.