What is the intended meaning to be understood from Allah's saying: (Do they not then تدبر (contemplate/ponder deeply) the Quran? Had it been from [any other] than Allah, they would have found within it much contradiction) in the context of the verses that precede and follow it?

Neglecting to ponder and reflect upon the verses of the Quran is among the causes of misguidance and deviation from obedience to Allah and His Messenger. If they were to ponder the Quran, they would realize that it is the truth revealed from Allah, and not from anyone else; for there is no discrepancy or contradiction within it. Pondering the Quran necessitates certainty that it is the truth and the veracity, and that it is from Allah, and by it hearts are put at ease.