Abu Hurairah (May Allah be pleased with him) said:
The Messenger of Allah (ﷺ) said, "It is not lawful for a Muslim to forsake his (Muslim) brother beyond three days; and whosoever does so for more than three days, and then dies, will certainly enter the Hell."[Abu Dawud]. (PT)
App reference (PT): Book 18, Hadith 85 (PT)
Arabic/English book reference (PT): Book 18, Hadith 1595 (PT)