Hadith: May his nose be rubbed in dust, then may his nose be rubbed in dust, and may his nose be rubbed in dust." It was said: "O Messenger of Allah, who? He said: "The one whose parents, one of them or both, reach old age in his life yet he does not enter Paradise

عَنْ أَبِي هُرَيْرَةَ رضي الله عنه عَنِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ قَالَ:
«رَغِمَ أَنْفُ، ثُمَّ رَغِمَ أَنْفُ، ثُمَّ رَغِمَ أَنْفُ»، قِيلَ: مَنْ؟ يَا رَسُولَ اللهِ قَالَ: «مَنْ أَدْرَكَ أَبَوَيْهِ عِنْدَ الْكِبَرِ، أَحَدَهُمَا أَوْ كِلَيْهِمَا فَلَمْ يَدْخُلِ الْجَنَّةَ».
[صحيح] - [رواه مسلم] - [صحيح مسلم: 2551]

Abu Hurayrah (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said:
"May his nose be rubbed in dust, then may his nose be rubbed in dust, and may his nose be rubbed in dust." It was said: "O Messenger of Allah, who? He said: "The one whose parents, one of them or both, reach old age in his life yet he does not enter Paradise."
[Authentic hadith] - [Narrated by Muslim] - [Sahih Muslim - 2551]

Explanation

The Prophet (may Allah's peace and blessings be upon him) invoked humiliation and disgrace to the extent that it was as if he had put his nose in the dust - repeating this thrice. He was, thus, asked: O Messenger of Allah, who is this one against whom you supplicated?
He (may Allah's peace and blessings be upon him) said: The one whose parents—one of them or both—reached old age in his life, and they were not a means of admitting him to Paradise given his unkindness and undutifulness towards them.