Hawzah News Agency – Imam al-Sadiq peace be upon him says:

أوّلُ ما يُتحَفُ بهِ المؤمنُ يُغفَرُ لِمَن تَبِعَ جَنازتَهُ.

'The first gift that a believer is able to bestow [others after his death] is that those who follow his funeral procession are forgiven.'

Source: al-Kafi, v. 3, p. 173, no. 3