The Messenger of Allah (ﷺ) said: "People should certainly stop lifting their gaze to the sky when they supplicate during the prayer, or they will lose their eyesight."
Sunan an-Nasa'i Book 13, Hadith 98
← Previous Hadith When the Messenger of Allah (ﷺ) sat to say the tashahhud, he placed his left hand on his left thigh and pointed with his forefinger, and his gaze did not go beyond he finger with which he was pointing.

Sunan an-Nasa'i Book 13, Hadith 97 Next Hadith → "Before the tashahhud was enjoined, when we prayed we used to say: 'Peace (As-Salam) be upon Allah (SWT), pace be upon Jibril, peace be upon Mika'il.' The Messenger of Allah (ﷺ) said: 'Do not say this, for indeed Allah (SWT), the Mighty and Sublime, is As-Salam. Rather say: "At-tahiyyatu lillahi wasalawatu wat-tayibaat, as-salamu 'alaika ayah-Nabiyyu wa rahmatAllahi wa baraktuhu. As-salamu 'alaina a 'ala ibad illahis-salihin, ashadu an la ilaha ill Allah, wa ashhadu anna Muhammadan 'abduhu wa rasuluhu. (All compliments, prayers and pure words are due to Allah. Peace be upon you O Prophet, and the mercy of Allah and His blessings. Peace be upon us and upon the righteous slaves of Allah. I bear witness that that none has the right to be worshipped except Allah, and I bear witness that Muhammad is His slave and messenger.)"

Sunan an-Nasa'i Book 13, Hadith 99