Sahih Al-Bukhari — Hadith #831

`Abdullah said, "Whenever we prayed behind the Prophet (ﷺ) we used to recite (in sitting) 'Peace be on Gabriel, Michael, peace be on so and so. Once Allah's Messenger (ﷺ) looked back at us and said, 'Allah Himself is As-Salam (Peace), and if anyone of you prays then he should say, at-Tahiyatu li l-lahi wa ssalawatu wa t-taiyibat. As-salamu `alalika aiyuha n-Nabiyu wa rahmatu l-lahi wa barakatuh. Assalamu `alaina wa `ala `ibadi l-lahi s-salihin. (All the compliments, prayers and good things are due to Allah; peace be on you, O Prophet, and Allah's mercy and blessings [be on you]. Peace be on us an on the pious subjects of Allah). (If you say that, it will reach all the subjects in the heaven and the earth). Ash-hadu al-la ilaha illa l-lah, wa ash-hadu anna Muhammadan `Abduhu wa Rasuluh. (I testify that there is no Deity [worthy of worship] but Allah, and I testify that Muhammad is His slave and His Apostle).