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]. (JA)
App reference (JA): Book 18, Hadith 85 (JA)
Arabic/English book reference (JA): Book 18, Hadith 1595 (JA)