وَإِنَّ رَبَّكَ هُوَ يَحْشُرُهُمْ ۚ إِنَّهُۥ حَكِيمٌ عَلِيمٌ
Wa inna Rabbaka Huwa yahshuruhum; innahoo Hakeem 'Aleem
[Prophet], it is your Lord who will gather them all together: He is all wise, all knowing.
And indeed, your Lord will gather them together. He is all-wise, all-knowing.
Hashr means mustering, driving people together from every quarter and assembling them in one place; Arabic uses it of armies and of locusts. It arrives directly after the count of who went ahead and who lagged behind, so whoever kept that record is also the one who convenes the assembly. The pair of names closing the verse answers that split, knowledge for the counting and wisdom for the gathering.