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