Sayyiduna Abdullah (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) said: "The best people are those of my generation, then those who come after them, then those who come after them." The narrator says: I do not know whether he said it a third or a fourth time. "Then after them people will come whose testimony will precede their oath, and whose oath will precede their testimony."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20598
Sayyiduna Imran bin Husayn (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him) that he (peace and blessings be upon him) said: "My generation is the best, then those who come after them. Then a people will come who will make vows but not fulfil them, who will swear oaths without being asked to swear, who will betray and will not be trustworthy, who will testify without being asked to testify, and obesity will become widespread among them."
Abu al-Fadl relates in his narration: I heard Ahmad bin Salamah saying that the words "they will swear oaths" occur only in the narration of Hisham among the students of Qatadah. This addition is narrated only by Mu'adh bin Hisham from his father.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20599
Imran bin Husayn (may Allah be pleased with him) says that the Messenger of Allah (peace and blessings be upon him) said: "The best era of my Ummah is my era, in which I was sent, then the one after them, then the one after them. Then a people will come who will make vows and not fulfil them, who will betray and not be trustworthy, who will testify without being asked to testify, and obesity will become widespread among them." This is how all of Hisham's students narrate it, without mention of swearing; if Mu'adh preserved it, the mention of swearing in it agrees with (the hadith of) Ibn Mas'ud (may Allah be pleased with him). It is possible that what is meant regarding testimony is that he testifies to something he did not witness and does not know, so he becomes a false witness.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20600