ENOfficial
`Imran b. Husain told that he heard God's messenger say, "Between the creation of Adam and the coming of the last hour there is no more serious matter than the dajjal." Muslim transmitted it.
Source: sunnah.com
Other translations
Arabic
وَعَنْ عِمْرَانَ بْنِ حُصَيْنٍ قَالَ: سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ: «مَا بَيْنَ خَلْقِ آدَمَ إِلَى قِيَامِ السَّاعَةِ أَمْرٌ أكبر من الدَّجَّال» . رَوَاهُ مُسلم
sunnah.com