that the Prophet (ﷺ) said: "Allah Most High said: 'I have prepared for My righteous worshipers what no eye has seen, no ear has heard, and no human heart has conceived.'" And that is testified to in Allah's Book: No person knows what is kept hidden for them of delights of the eyes (32:17).
Jami` at-Tirmidhi Book 47, Hadith 249