"He said, 'The Truth, and the Truth I speak.'" Al-Hasan's interpretation is that this is an oath, saying: (It is) the Truth, the Truth, I shall surely fill Hell.
Al-Hakam ibn 'Utaybah recited: "Qala fal-haqqu wal-haqqa aqulu" (He said: And the Truth, and the Truth I speak), meaning: Allah is the Truth.