Sayyiduna Ibn Umar (may Allah be pleased with them both) narrates that he said to me: "Love for the sake of Allah, hate for the sake of Allah, befriend for the sake of Allah, and take as enemy for the sake of Allah, for the friendship (wilayah) of Allah is attained only through this. And no man tastes the sweetness of faith, however much he prays and fasts, until he becomes like this; yet people's brotherhood has come to be over the affairs of this world, and that will not benefit its people at all."
And Ibn Umar (may Allah be pleased with them both) said to me: "When you reach the morning, do not talk to yourself about the evening, and when you reach the evening, do not talk to yourself about the morning. Take from your health for your sickness, and from your life for your death, for, O Abdullah bin Umar, you do not know what your name will be tomorrow."
And the Messenger of Allah (peace and blessings be upon him) took hold of part of my body and said: "Be in this world like a stranger or a wayfarer, and count yourself among the people of the graves."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 13480