﴿ قَيِّمًۭا لِّيُنذِرَ بَأْسًۭا شَدِيدًۭا مِّن لَّدُنْهُ وَيُبَشِّرَ ٱلْمُؤْمِنِينَ ٱلَّذِينَ يَعْمَلُونَ ٱلصَّٰلِحَٰتِ أَنَّ لَهُمْ أَجْرًا حَسَنًۭا ﴾

“[a divine writ] unerringly straight, meant to warn [the godless] of a severe punishment from Him, and to give unto the believers who do good works the glad tiding that theirs shall be a goodly reward-”

a Book upright qayyiman is a second circumstantial qualifier for added emphasis to warn of to make by this Book the disbelievers fear severe chastisement from Him from God and to bring to the believers who perform righteous deeds the good tidings that theirs will be a fair reward