Jarir bin 'Abdullah (May Allah be pleased with him) said:
I asked the Messenger of Allah (ﷺ) about (the Islamic ruling on) accidental glance (i.e., at a woman one is not Islamically allowed to look at) and he ordered me to turn my eyes away.[Muslim]. (JA)
App reference (JA): Book 18, Hadith 115 (JA)
Arabic/English book reference (JA): Book 18, Hadith 1625 (JA)