The Messenger of Allah ﷺ said, "Toward the place where the sun sets, there is an open gate whose width spans seventy years of travel. That gate remains open for repentance until the sun rises from its direction. Once the sun rises from there, no soul will benefit from its faith if it had not believed before or earned good through its faith."
قال رسول الله ﷺ: إن من قبل مغرب الشمس بابا مفتوحا، عرضه سبعون سنة، فلا يزال ذلك الباب مفتوحا للتوبة حتى تطلع الشمس من نحوه، فإذا طلعت من نحوه لم ينفع نفسا إيمانها لم تكن آمنت من قبل أو كسبت في إيمانها خيرا.
Ibn Majah (4070) narrated it from Abu Bakr bin Abu Shayba, who said, "Ubaydullah bin Musa related to us, from Israil, from Asim (that is, Ibn Abu Najud), from Zirr (that is, Ibn Hubaysh), from Safwan bin Assal," who said, and he related it.Tirmidhi (3535, 3536) and Ahmad (18095) also narrated it, and Ibn Hibban (1321) graded it sahih, all of them through another route, from Asim, at greater length, as mentioned in the Book of Repentance. Its chain of transmission is hasan, on account of Asim bin Abu Najud.