On such occasions, when Rasulullah (sallallahu ‘alaihi wasallam) happened to pass by, he would pass his blessed hands over the head of Hazrat ‘Ammaar (radhiyallahu ‘anhu) and say:

يا نار كوني بردا وسلاما على عمار كما كنت على إبراهيم

O fire! Become cool and safe for ‘Ammaar as you had become for Nabi Ebrahim (‘alaihis salaam)

Whenever Rasulullah (sallallahu ‘alaihi wasallam) would see Hazrat ‘Ammaar, his father, Hazrat Yaasir, or his mother, Hazrat Sumayyah (radhiyallahu ‘anhum), he would advise them saying, “O family of Yaasir! Exercise patience!” Sometimes, Rasulullah (sallallahu ‘alaihi wasallam) would also utter, “O Allah! Forgive the family of Yaasir!” At times, he would remark, “Glad tidings to you! Jannah eagerly awaits your arrival!”

Hazrat ‘Ali (radhiyallahu ‘anhu) reports that he heard Rasulullah (sallallahu ‘alaihi wasallam) saying, “From head to toe, Hazrat ‘Ammaar (radhiyallahu ‘anhu) is imbued with faith (i.e. he is an embodiment of Imaan).”

(Extracted from Seeratul Mustafa 1/226)