Moving to Rabzah:

Hazrat Abu Zar (radhiyallahu ‘anhu) remained in Shaam until the era of Hazrat Uthmaan (radhiyallahu ‘anhu). During the rule of Hazrat Uthmaan (radhiyallahu ‘anhu), Hazrat Mu‘aawiyah (radhiyallahu ‘anhu), the governor over Shaam, wrote to Hazrat Uthmaan (radhiyallahu ‘anhu) and mentioned that the people were complaining about Hazrat Abu Zar (radhiyallahu ‘anhu) on account of the great degree of abstinence of the dunya which he possessed. Hazrat Abu Zar (radhiyallahu ‘anhu) had a natural aversion for wealth and would insist that those people who possessed extra wealth should give their extra wealth away in sadaqah. Hazrat Uthmaan (radhiyallahu ‘anhu) therefore summoned him from Shaam and asked him to stay in Rabzah. Rabzah is a place approximately three day’s journey from Madinah Munawwarah.

(Usdul Ghaabah 1/344, Siyar A’laam min Nubalaa 3/393, Mu’jamul Buldaan 3/24)