There will be rulers over you who abandon part of the Sunnah

It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that he said: "Rulers will be imposed over you who will abandon this much of the Sunnah," and he pointed to the tip of his finger. "And if you leave them as they are, they will bring about a great calamity. The reality is that for every nation that abandoned its religion, it began with abandoning the Sunnah, and the last thing they will abandon will be the prayer; and were it not that they felt shame before people, they would not pray either."
This hadith is sahih (authentic) on the condition of the two Shaykhs, but they did not record it.

It is narrated from Sayyiduna Hudhayfah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) sent an expedition towards Dumat al-Jandal and instructed: "Go, and you will find Ukaydir, the ruler of Dumah, outside the town hunting game; so seize him." So they went and found him just as he (peace and blessings be upon him) had said, and they seized him. Meanwhile the people of the town shut themselves up in the fortress and began to look down on the Muslims from above and talk with them. One of the Muslims said to one of the people of the fortress: I ask you by Allah, do you find mention of Muhammad (peace and blessings be upon him) in your scripture? He said: No. Then another man standing beside him said: We find him in our scripture as one who has the qualities of Quraysh (but along with this he said some improper words). That Muslim asked: O Abu Bakr, have these people not disbelieved? He said: Yes, and you too will soon disbelieve. Then, when the army returned and Musaylimah the Liar claimed prophethood, that man asked Sayyiduna Abu Bakr (may Allah be pleased with him): Do you remember your statement which you made at Dumat al-Jandal, that you too will disbelieve? Was this affair of Musaylimah what was meant by it? He said: No, rather that will be at the end of time.
The chain of this hadith is sahih (authentic), but the two Shaykhs did not record it.