Narrated 'Abdullah bin Mas'ud:
that the Messenger of Allah (ﷺ) said: "The best generation is my generation, then those who follow them, then those who follow them. Then comes a people after that whose swearing precedes their testimony, or whose testimony precedes their swearing." (JA)
English reference (JA): Vol. 1, Book 46, Hadith 3859 (JA)
Arabic reference (JA): Book 49, Hadith 4232 (JA)