Hawzah News Agency – The merciful prophet of Islam (pbuh) says:

إنَّ أعجَلَ الخَيرِ ثَواباً صِلةُ الرَّحِمِ.

'Verily the good deed to be rewarded the fastest is reconciliation with one's kin.'

Source: al-Kafi, v. 2, p. 152, no. 15