From Sahih Muslim (Hadith 6469):
Abdullah reported Allah's Messenger (ﷺ) as saying:The best of my Umma would be those of the generation nearest to mine. Then those nearest to them, then those nearest to them, then people would come whose witness would precede the oath and the oath will precede the witness. Hannad has not made the mention of Qarn in his narration. Qutaiba said that, instead of the word Qaum, the word Aqwam has been used
Reference: Muslim 6469