Ibn 'Umar (May Allah be pleased with them) reported:
The Prophet (ﷺ) as saying: "The worst of lies is to pretend to have seen something which he has not seen."[Al- Bukhari]. (ID)
App reference (ID): Book 18, Hadith 35 (ID)
Arabic/English book reference (ID): Book 18, Hadith 1545 (ID)