It is narrated from Sayyiduna Mu'adh bin Anas al-Juhani (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Allah has some servants to whom Allah Almighty will not speak on the Day of Resurrection, nor will He purify them, and for them is a painful punishment." It was said: O Messenger of Allah! Who are they? He (peace and blessings be upon him) said: "One who disowns his parents and turns away from them, one who disowns his child, and a man upon whom some people bestowed a favour, and he denied their favour and disowned them."
It is narrated from Sayyiduna Mu'adh bin Anas al-Juhani (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "My Ummah will remain upon a good way as long as three things do not appear among them: as long as knowledge is not taken away from them, illegitimate children do not become many among them, and the 'Saqqarun' do not appear among them." It was said: O Prophet of Allah! Who are the Saqqarun? He (peace and blessings be upon him) said: "A generation that will arise at the end of time, whose greeting among themselves will be cursing one another."
Hadith Referenceالمعجم الكبير للطبراني / باب الميم / 17573