بُلُوغُ الْمَرَامِ
Bulugh al-Maram 314
The Book of Prayer
وَعَنْ عَبْدِ اَللَّهِ بْنِ مَسْعُودٍ - رضى الله عنه - قَالَ : { اِلْتَفَتَ إِلَيْنَا رَسُولُ اَللَّهِ - صلى الله عليه وسلم -فَقَالَ : " إِذَا صَلَّى أَحَدُكُمْ فَلْيَقُلْ : اَلتَّحِيَّاتُ لِلَّهِ , وَالصَّلَوَاتُ , وَالطَّيِّبَاتُ , اَلسَّلَامُ عَلَيْكَ أَيُّهَا اَلنَّبِيُّ وَرَحْمَةَ اَللَّهِ وَبَرَكَاتُهُ , اَلسَّلَامُ عَلَيْنَا وَعَلَى عِبَادِ اَللَّهِ اَلصَّالِحِينَ , أَشْهَدُ أَنْ لَا إِلَهَ إِلَّا اَللَّهُ , وَأَشْهَدُ أَنَّ مُحَمَّدًا عَبْدُهُ وَرَسُولُهُ , ثُمَّ لِيَتَخَيَّرْ مِنْ اَلدُّعَاءِ أَعْجَبُهُ إِلَيْهِ , فَيَدْعُو } مُتَّفَقٌ عَلَيْهِ , وَاللَّفْظُ لِلْبُخَارِيِّ . [1]
Narrated 'Abdullah bin Mas'ud (RA): Allah's Messenger (ﷺ) looked at us and said, "When one of you is (sitting) in prayer, he should say, 'All services reported by words, by prayers (acts of worship), and all good things are due to Allah, peace be upon you, O Prophet, and Allah's mercy and blessings, peace be upon us and upon Allah's upright slaves. I testify that nothing deserves to be worshipped except Allah and I testify that Muhammad is His slave and Messenger.' Then he may choose any supplication which pleases him most and recite it." [Agreed upon, and this wording is from al-Bukhari].
Sunnah.com reference: Book 2, Hadith 203