The Book of Virtue, Enjoining Good Manners, and Joining of the Ties of Kinship
وَحَدَّثَنِي عَبْدُ الْمَلِكِ بْنُ شُعَيْبِ بْنِ اللَّيْثِ، حَدَّثَنِي أَبِي، عَنْ جَدِّي، حَدَّثَنِي عُقَيْلُ بْنُ، خَالِدٍ قَالَ قَالَ ابْنُ شِهَابٍ أَخْبَرَنِي أَنَسُ بْنُ مَالِكٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " مَنْ أَحَبَّ أَنْ يُبْسَطَ لَهُ فِي رِزْقِهِ وَيُنْسَأَ لَهُ فِي أَثَرِهِ فَلْيَصِلْ رَحِمَهُ " .Anas b. Malik reported that Allah's Messenger (ﷺ) said:He who likes that his sustenance should be expanded and his age may be lengthened should join the tie of kinship
From Sahih Muslim, whose reports the scholars accept as authentic.