Translation:

54. When those come to thee who believe in Our Signs say: "Peace be on you: your Lord had inscribed for Himself (the rule of) Mercy: verily if any of you did evil in ignorance and thereafter repented and amended (his conduct) lo! He is Oft-Forgiving Most Merciful."

Notes (Tafseer)

873. The humble who had sincere faith, were not only not sent away to humour the wealthy: they were honoured and were given a special salutation, which has become the characteristic salutation in Islam: "Peace be on you,"-the word peace, "salam" having special affinity with the word "Islam." In words they are given the salutation; in life they are promised Mercy by the special grace of God.

874. Cf. vi 12.