The Prophet ﷺ said, "The master of seeking forgiveness is to say, 'O Allah, You are my Lord. There is no god but You. You created me, and I am Your servant. I hold to Your covenant and promise as best I can. I seek refuge in You from the evil of what I have done. I acknowledge before You Your favors upon me, and I acknowledge before You my sins, so forgive me, for none forgives sins but You.'"He said, "Whoever says it during the day with firm conviction in it and dies that same day before evening will be among the people of Paradise, and whoever says it during the night with firm conviction in it and dies before morning will be among the people of Paradise."In another wording, "If he says it when evening comes and then dies, he will enter Paradise," or "he will be among the people of Paradise, and if he says it when morning comes and dies that same day, the same applies."
عن النبي ﷺ: سيد الاستغفار أن تقول: اللهم أنت ربي، لا إله إلا أنت خلقتني وأنا عبدك، وأنا على عهدك ووعدك ما استطعت، أعوذ بك من شر ما صنعت، أبوء لك بنعمتك علي، وأبوء لك بذنبي فاغفر لي فإنه لا يغفر الذنوب إلا أنت. قال: ومن قالها من النهار موقنا بها فمات من يومه قبل أن يمسي فهو من أهل الجنة، ومن قالها من الليل وهو موقن بها فمات قبل أن يصبح فهو من أهل الجنة. وفي لفظ: إذا قال حين يمسي فمات دخل الجنة أو كان من أهل الجنة، وإذا قال حين يصبح فمات من يومه مثله.
Bukhari narrated it in the Book of Supplications (6306) from Abu Muamar, who said, our teacher Abdul-Warith told us, Husayn (that is, al-Muallim) told us, Abdullah bin Burayda told us, from Bashir bin Kaab Adawi, who said, Shaddad bin Aws told me, and then he related it. He also narrated it (6323) via the route of Yazid bin Zuray, from Husayn, with a similar wording, containing the second version.Something similar in meaning was reported from Abdullah bin Burayda, from his father, from the Prophet ﷺ, who said, "Whoever says, upon waking or upon reaching evening, 'O Allah, You are my Lord, there is no god but You, You created me, and I am Your servant, and I hold to my covenant and promise to You as best as I can, I seek refuge in You from the evil of what I have done, I acknowledge Your favor upon me, and I acknowledge my sin, so forgive me, for none forgives sins except You,' and then dies that day or that night, will enter Paradise."Abu Dawud (5070), Ibn Majah (3872), Ahmad (23013), Nasai in Amal al-Yawm wal-Layla (20, 579), Ibn Hibban (1035), and Hakim (1/514-515) all narrated it through various routes from Walid bin Thalaba Tai, from Abdullah bin Burayda, from his father, who related it.Nasai said following the hadith (580), "Husayn is more reliable in our view than Walid bin Thalaba, and more knowledgeable about Abdullah bin Burayda, and his hadith is more likely to be correct."I say, Husayn al-Muallim narrated it from Abdullah bin Burayda, from Bashir bin Kaab Adawi, from Shaddad bin Aws, as mentioned above. Mizzi, in the biographical entry on Munzir bin Thalaba in Tahzib Kamal (7/224), after presenting the disagreement over its chain of transmission, affirmed decisively that the hadith of Shaddad bin Aws is the one that is preserved.I say, the hadith was also reported through the route of Sulayman bin Burayda, from his father as well, but its central figure is Layth bin Abu Salim, who suffered from confusion of memory in his later years, and so his hadith became disordered. He was indeed inconsistent regarding this hadith.As for Hakim, he said, "This is a hadith sahih in its chain of transmission." Likewise, everyone who judged it sahih did so by looking at the surface of the chain of transmission, and allowed for the possibility that the hadith could exist with Abdullah bin Burayda in both forms. But the correct view in my opinion is that it belongs to the hadith of Shaddad bin Aws, and whoever attributed it to the musnad of Burayda simply followed the well-trodden path. This is supported by the agreement in wording between the two hadiths.