Tirmidhi

Explanation:
1:
That is: Say salam to the people of Ansar,
In this is the virtue of the Ansar.

Note:
(In the chain, Muhammad bin Thabit Banani is a weak narrator,
but its second portion is authentic due to supporting evidences,
al-Sahihah: 3096)

Hadith Commentary:
That is, other undeserving people will be appointed to positions, and you will be deprived, and this is exactly what happened during the era of Banu Umayyah. The prophecy of the Messenger of Allah (sallallahu alayhi wa sallam) was fulfilled word for word. However, the Ansar truly exercised patience and fully acted upon the Prophet’s (sallallahu alayhi wa sallam) advice.
Radi Allahu anhum wa radu anhu—this refers to the time when Abdul Malik ibn Marwan persecuted Anas (radi Allahu anhu), and he traveled from Basra to Damascus to present his complaints to Walid ibn Abdul Malik. In the end, Walid ibn Abdul Malik (the ruler of the time) restored his right to him.
(Fath al-Bari)

Hadith Commentary:
➊
Regarding the Ansar, the Messenger of Allah (sallallahu alayhi wa sallam) said:
“After me, you will soon face preferential treatment. Others who are not deserving will be appointed to positions of authority, and you will be deprived.”
Indeed, this is exactly what happened during the era of Banu Umayyah; the prophecy of the Messenger of Allah (sallallahu alayhi wa sallam) was fulfilled word for word. However, the Ansar truly exercised patience and fully acted upon the prophetic counsel.
➋
The incident of the departure of Anas (radi Allahu anhu) mentioned in the hadith occurred when the governor of Basrah, Hajjaj, harassed him, so he went to Damascus and complained to Walid ibn Abd al-Malik.
Eventually, the governor of Damascus granted him his due right.
(Fath al-Bari: 7/149)