And when the reason for the denial was the concealment of what the visions of the minds reveal from the proofs, and the estimation was: indeed, it is good news for the believers, but it was hidden because the context was for the threat of the Day of Resurrection, he turned to his saying, affirming what they have of the denial of it.

﴿And indeed, it﴾ meaning the great Qur'an ﴿is a source of regret﴾ meaning for what they see of its interpretation in this world and the Hereafter ﴿upon the disbelievers﴾ meaning those deeply entrenched in disbelief because they denied it due to what is apparent to them of their punishment and the reward of the believers.