Like so many of the teachings of our Lord, this saying of His illustrates a general truth, equally valid today; "only those who have ears to hear" will understand what He says through His word, the world in general is deaf to the appeals of the crucified One, it does not want to hear.
And (let it be whispered) quite a few of those who have heard His appeal fail to listen to His further revelations intelligently, often being too busy bickering amongst themselves over some fragmentary portion which they have heard, and misconstrued!