From Ibn Shihab who said that Anas bin Malik informed him that the Messenger of Allaah sallAllaahu alayhi wa sallam said:

” مَنْ أَحَبَّ أَنْ يُبْسَطَ لَهُ فِي رِزْقِهِ، وَيُنْسَأَ لَهُ فِي أَثَرِهِ ، فَلْيَصِلْ رَحِمَهُ “.

‘Whoever would like that his provisions are increased many-fold and that he has a long blessed life then he should keep good relations with his relatives.’

[Collected by Bukhari and Muslim]