Riyad as-Salihin

Abu Hurairah (May Allah be pleased with him) reported: The Prophet (ﷺ) said, "By Allah, he is not a believer! By Allah, he is not a believer! By Allah, he is not a believer." It was asked, "Who is that, O Messenger of Allah?" He said, "One whose neighbour does not feel safe from his evil".

[Al-Bukhari and Muslim].

Another narration of Muslim is: Messenger of Allah (ﷺ) said, "He will not enter Jannah whose neighbour is not secure from his wrongful conduct".