Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) related that between their (the Muslims') accepting Islam and the revelation of this verse, in which Allah reproaches them, there were only four years: "And let them not be like those who were given the Scripture before, and the time became long for them, so their hearts hardened; and many of them are defiantly disobedient" [Surah Al-Hadid: 16].
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9738