Paradise has eight gates; seven are closed and one is open for repentance

It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Paradise has eight gates; seven are closed, and one gate is open for repentance until the sun rises from its direction."

It is narrated from Sayyiduna Abu Sa'id al-Khudri (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Indeed, Satan said: O my Lord, by Your might, as long as the souls of Your servants remain in their bodies, I will keep leading them astray. So the Lord, the Mighty and Majestic, said: By My might and My majesty, as long as they keep asking Me for forgiveness, I will keep forgiving them."
This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Sayyiduna Abu al-Darda' (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Whatever a son of Adam speaks is written down against him. So if he commits a sin and wishes to repent to Allah, the Mighty and Majestic, let him go to an elevated place, spread both his hands towards Allah and say: 'Allahumma inni atubu ilayka minha an la arji'a ilayha abada' (O Allah, I repent to You from this sin with a repentance that I will never return to it). Then he is forgiven, as long as he does not return to that deed of his."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.

Ubadah bin Qurs (may Allah be pleased with him) states: "Indeed, nowadays you do deeds (sins) that in your eyes are finer (more trivial) than a hair, whereas in the time of the Messenger of Allah (peace and blessings be upon him) we used to count them among the destructive sins." The narrator says: I said to Sayyiduna Abu Qatadah (may Allah be pleased with him): What would he (Ubadah) have said if he had lived to see this time of ours?! He replied: This very thing; I say the same.
This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.

It is narrated from Umm Ismah al-Awsiyyah (may Allah be pleased with her) - who lived in the time of the Messenger of Allah (peace and blessings be upon him) - that the Messenger of Allah (peace and blessings be upon him) said: "Whenever a Muslim commits a sin, the angel appointed to record his sins waits for three hours. If he seeks Allah's forgiveness for that sin at any moment within those hours, the angel does not record it against him, and he will not be punished for it on the Day of Resurrection."
This hadith has a sahih (authentic) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.