Shama-il Tirmidhi Chapter 39, Hadith Number 14 (261).
The aayah is the last aayah of Surah Maa-idah:
In tu-adh-dhib-hum fa-innahum ‘ibaaduk. Wa in tagh-fir lahum fa-innaka antal azizul hakim.
Translation: “If Thou punish them, lo! they are Thy slaves, and if Thou forgive them, (lo! the are Thy slaves).Lo! Thou, only Thou, art Mighty, the wise”.Surah Maa-idah, 118.
The Being that possesses great power, if He wills, He may forgive the criminal. The One that is all Wise, there is Wisdom and benefit in every act of His. The reason for Sayyidina Rasulullah Sallallahu ‘Alayhi Wasallam reciting this aayah while standing and also in the ruku and sajdah, and repeating it many times, is to bring to mind the two attributes of Allah, namely the attributes of justice and forgiveness. The whole scene on the day of qiyaamah will be of these two things. It is stated that Imaam Aa’zam Abu Hanifah RA. also recited the following aayah the whole night:
Wamtaazul yauma ayyuhal mujrimun.
Translation: “But avaunt ye, O ye guilty, this day!” Surah Yaseen, 58.
In this aayah too the scene of qiyaamah is portrayed. That today the sinners should separate and distinguish themselves. What a severe and nerve-chilling command this is. Today they are together with the pious and holy people and benefiting from the barakaat (blessings) they receive, but at this moment the sinners will be separated from them. May the Most Merciful Allah with His Grace keep those pious souls under His shadow, otherwise it is really a time for great trials.