From Sahih Bukhari (Hadith 6658):
Narrated `Abdullah:The Prophet (ﷺ) was asked, "Who are the best people?" He replied: The people of my generation, and then those who will follow (come after) them, and then those who will come after the later; after that there will come some people whose witness will precede their oaths and their oaths will go ahead of their witness." Ibrahim (a sub-narrator) said, "When we were young, our elder friends used to prohibit us from taking oaths by saying, 'I bear witness swearing by Allah, or by Allah's Covenant
Reference: Bukhari 6658