“The Reckoner,” in the Day of Judgement. One of the ninety-nine attributes of God. The title occurs in the Qur’an three time.
Surah iv. 7: “God sufficeth for taking account.”
Idem. 88: “God of all things takes an account.”
Surah xxxiii. 39: “God is good enough at reckoning up.”
Based on Hughes, Dictionary of Islam