قَوْلُهُ تَعَالَى: {وَمَا يُعَمَّرُ مِنْ مَعْمَرٍ وَلَا يُنْقَصُ مِنْ عُمُرِهِ إِلَّا فِي كِتَابٍ} [فاطر: 11]

I heard Messenger of Allah ﷺ as saying: He who is desirous that his means of sustenance should be expanded for him or his age may be lengthened, should join the tie of relationship. (Using translation from Muslim 2557a)  

سَمِعْتُ رَسُولَ اللهِ ﷺ يَقُولُ «مَنْ سَرَّهُ أَنْ يُبْسَطَ عَلَيْهِ رِزْقُهُ أَوْ يُنْسَأَ فِي أَجَلِهِ فَلْيَصِلْ رَحِمَهُ»