It was narrated that Ibn 'Umar said:
"The Messenger of Allah (ﷺ)
said:
'Do not lift your gaze to the heavens lest your sight be
snatched away," meaning during prayer. (AR)
English reference (AR): Vol. 1, Book 5, Hadith 1043 (AR)
Arabic reference (AR): Book 5, Hadith 1096 (AR)