The Quran

وَيَومَ يَحشُرُهُم كَأَن لَم يَلبَثوا إِلّا ساعَةً مِنَ النَّهارِ يَتَعارَفونَ بَينَهُم ۚ قَد خَسِرَ الَّذينَ كَذَّبوا بِلِقاءِ اللَّهِ وَما كانوا مُهتَدينَ

Muhammad Asad

And on the Day when He shall gather them [unto Himself, it will seem to them] as if they had not tarried [on earth] longer than an hour of a day, knowing one another;¹ [and] lost indeed will be they who [in their lifetime] considered it a lie that they were destined to meet God, and [thus] failed to find the right way.

I.e., their past sojourn in this world, during which they were bound to one another by various ties of human relationship, will appear to them like a short moment as compared with the timeless duration of the life that awaits them after resurrection (see note 19 on 79:46), with all their past relationships cut asunder. See also 6:94, which describes the condition of the deniers of the truth on the Day of Resurrection: "And now, indeed, you have come unto Us in a lonely state, even as We created you in the first instance"; and later on, in that same verse: "Indeed, all the bonds between you [and your earthly life] are now severed...."