The 99 Names · Names Most Often Paired in the Quran
Al-Haqq الحق
The Truth in His essence and attributes: His word is true, His actions are true, meeting Him is true, and His religion is the truth.
Explanation
A detailed explanation of this name (in Arabic) is in: Sharh Asma' Allah al-Husna fi Daw' al-Kitab wa al-Sunnah — Dr. Sa'eed ibn 'Ali ibn Wahf al-Qahtani — p. 180 ↗
Evidence
﴿يَوۡمَئِذࣲ يُوَفِّيهِمُ ٱللَّهُ دِينَهُمُ ٱلۡحَقَّ وَيَعۡلَمُونَ أَنَّ ٱللَّهَ هُوَ ٱلۡحَقُّ ٱلۡمُبِينُ ٢٥﴾
Call upon Allah by this name
“To Allah belong the Beautiful Names, so call upon Him by them” — Al-A'raf 180
From the Prophetic Sunnah
From the opening supplication of the night prayer
«ولك الحمد أنت الحق ووعدك الحق وقولك الحق ولقائك الحق والجنة حق والنار حق»
Sahih al-Bukhari (1120) and Sahih Muslim (769)
Grading: Agreed upon (al-Bukhari and Muslim)