And he says 'the Truth,' and it is also an oath.
Interpretation of verses 86 through 88 of Surah Sad.
وَيَقُول الحقَّ وَهُوَ قسمٌ أَيْضا.
تَفْسِير الْآيَات من ٨٦ وَحَتَّى ٨٨ من سُورَة ص.