Ammar bin Yasir reported,
I heard the Messenger of Allah ﷺ say in his prayer, "O Allah, by Your knowledge of the unseen and Your power over creation, keep me alive so long as You know that life is best for me, and take me when You know that death is best for me. O Allah, I ask You for awe of You in private and in public. I ask You for the word of truth in times of contentment and anger. I ask You for moderation in poverty and in wealth. I ask You for a blessing that never ends, and for a delight of the eye that never ceases. I ask You for contentment after Your decree, and for the coolness of life after death. I ask You for the pleasure of gazing upon Your Face, and the longing to meet You, without any harmful affliction or misleading trial. O Allah, adorn us with the beauty of faith, and make us guides who are themselves rightly guided."
Azami 2189
Sahihعن عمار بن ياسر قال
سمعت رسول الله ﷺ يقول في صلاته: اللهم بعلمك الغيب، وقدرتك على الخلق أحيني ما علمت الحياة خيرا لي، وتوفني إذا علمت الوفاة خيرا لي، اللهم أسألك خشيتك- يعني في الغيب والشهادة، وأسألك كلمة الحق في الرضا والغضب، وأسألك القصد في الفقر والغنى، وأسألك نعيما لا ينفد، وأسألك قرة عين لا تنقطع، وأسألك الرضا بعد القضاء، وأسألك برد العيش بعد الموت، وأسألك لذة النظر إلى وجهك، والشوق إلى لقائك في غير ضراء مضرة، ولا فتنة مضلة، اللهم زينا بزينة الإيمان، واجعلنا هداة مهتدين.
Nasai (1305) narrated it through Hammad bin Zayd, who said, Ata bin Saaib bin Malik told us, from his father, who said, Ammar bin Yasir led us in a prayer and made it brief. Some of the people said to him, "You have shortened," or "made brief the prayer." He said, "There is no blame on me for that, for I made supplications in it that I heard from the Messenger of Allah ﷺ." When he stood up, a man from the group, who was Ata's father though he referred to himself in the third person, followed him and asked him about the supplication. He then came and told the people, and mentioned the supplication.Its chain is sahih. Ata bin Saaib is trustworthy, and the imams affirmed his trustworthiness, though he became confused in his later years. However, Hammad bin Zayd's narration from him was before that confusion occurred.This was also narrated through Hammad bin Zayd by Ibn Hibban (1971) and Hakim (1/524), who said, "Sahih in chain." Hammad bin Salama also narrated it in agreement with him, and through his route Bayhaqi narrated it in Asma wa Sifat (244), as did Fudayl bin Ghazwan, through whose route Abu Yaala narrated it (1621, edition of Athari). All three of them narrated it from Ata bin Saaib in the same manner. However, Fudayl's hearing from Ata came after his confusion set in, but the agreement of the two Hammads with him confirms that he had not become confused regarding this particular hadith.For this reason, many scholars of hadith relied on this hadith as evidence for the believers seeing the Lord 
on the Day of Resurrection. Among them are Imam Ibn Khuzayma in his book Tawhid (p. 12), Ibn Manda in Radd Ali Jahmiya (86), Lalikai in Usul Itiqad Ahl Sunnah (844), and Bayhaqi in Asma wa Sifat (244).This hadith has another route, narrated by Nasai (1306), Tabarani in Dua (625), Bazzar in his Musnad (1392), and Imam Ahmad in his Musnad (18325). All of them narrated it through Sharik, from Abu Hashim, from Abu Majliz, who said, Ammar led us in a prayer and made it brief, so they objected to that. He said, "Did I not complete the ruku and sujud?" They said, "Yes indeed." He said, "Well, I made a supplication in them, one that the Messenger of Allah ﷺ used to make," and he then mentioned the supplication.In this chain is Sharik bin Abdullah Nakhai, whose memory has been criticized, though he did not err in narrating this particular hadith, since there are supporting narrations for it overall.