أَنَّ النَّبِيَّ – صَلَّى الله عَلَيْهِ وسَلَّمَ – فَقَدَ كَعْباً، فَسَأَلَ عَنْهُ؛ فَقَالُوا: مَرِيْضٌ، فَخَرَجَ يَمْشِي حَتَّى أَتَاهُ، فَلَمَّا دَخَلَ عَلَيْهِ قَالَ: أَبْشِرْ يَا كَعْبُ! فَقَالَتْ أُمُّهُ: هَنِيْئاً لَكَ الجنَّةُ يَا كَعْبُ! فَقَالَ: مَنْ هَذِهِ الْمُتَأَلِّيَةُ عَلَى اللهِ؟ ! قَالَ: هِيَ أُمِّي يَا رَسُولَ اللهِ! فَقَالَ: وَمَا يُدْرِيْكَ يَا أُمَّ كَعْبٍ؟ ! لَعَلَّ كَعْباً قَالَ مَا لاَ يَعْنِيْهِ، أَوْ مَنَعَ مَا لاَ يُغْنِيْهِ

From Ka’b ibn Ujrah, may Allaah be pleased with him, “That the Prophet, صلى الله عليه وسلم, missed Ka’b and so asked about him, they replied, “He is ill.”  So the Prophet, صلى الله عليه وسلم, left and walked until he came to him.  When he entered upon Ka’b, he said, “Receive the glad tidings, O Ka’b!” So his mother said, “O Ka’b, congratulations!  For you is Paradise!”  The Prophet, صلى الله عليه وسلم, said, “Who is the one who is taking an oath upon Allaah [that Ka’b has a place in Paradise]?”  Ka’b replied, “She is my mother, O Messenger of Allaah.”  So he, صلى الله عليه وسلم, replied, “And how do you know, O mother of Ka’b [that he is going to Paradise]?  Maybe Ka’b spoke about something which did not concern him or he withheld giving something which was insignificant?”[1]

As-Saheehah | no., 3103

[1] [i.e., would not have harmed him if he had given it, like wealth, knowledge, small kindnesses as mentioned in Surah Maa’oon, see Mullaa Ali Qaari’s explanation of the hadith of Anas (no. 4842) in Mishkaatul-Masaabih, والله أعلم] .

Note: Clarifications between square brackets [] and footnotes are those of the translator.