Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) said: "A time will come upon the people when a man will come to a grave and say: 'Would that I were in the place of my companion (in this grave).' He will not wish this out of love of meeting Allah, but because of the affliction he sees (among the living)."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9714