Imaam al-Barbahaaree said:
"And that we do not contend with or attempt to take away the command
from those assigned with it (i.e., the rulers) due to the saying of
the Messenger: "There are three things towards which the heart of a
Muslim never shows hatred or rancour:
1. Making ones action sincerely for the sake of Allaah,
2. Giving obedience to the rulers (wulatul-amr) and
3. Sticking to the group (jamaa'ah) for verily, their supplication
encompasses those who are behind them (i.e. those whom they rule
This is confirmed in His saying:
"O you who believe! Obey Allaah and obey the Messenger, and those of
you (Muslims) who are in authority". [an-Nisaa (4):59]
And that the sword is not to be raised against (any of) the Ummah of
Muhammad (sallallaahu alaihi wasallam).
And al-Fudayl said, "If I had a supplication that would be answered,
I would not make it except for the leader (imaam) because when the
leader becomes righteous, the towns and servants become safe and
Ibn al-Mubaarak said (in reference to the above saying of
al-Fudayl), "O teacher of goodness, who would show boldness towards
this besides you?"
[End of the words of Bukhaaree]
Imaam al-Barbahaaree (d. 329H) also said, "Whoever rebels against a
Muslim ruler is one of the Khawaarij, has caused dissent within the
Muslims, has contradicted the narrations and has died the death of
the days of ignorance." (Sharhus-Sunnah [p.42])
The Khawaarij are a group who first appeared in the time of 'Alee.
They split from his army and began the grave innovation of takfeer
(declaring Muslims, rulers or the ruled, in their view guilty of
major sins, to be unbelievers). The Prophet s warned against them
in many authentic ahaadeeth, "They are the dogs of
He also informed us that they would continue to appear until the end
of this world, saying, "A group will appear reciting the Qur'aan, it
will not pass beyond their throats, every time a group appears it
will be cut off, until the Dajjaal appears within them." 
Imaam Al-Barbahaaree (d.329H) also said, "It is not permissible to
fight the ruler or rebel against him even if he oppresses. This is
due to the saying of the Messenger of Allaah to Aboo Dharr
al-Ghifaaree, "Have patience even if he is an Abyssinian slave,"
 and his saying to the Ansaar, "Have patience until you meet me
at the Pool," (reported by Bukharee from Usayd ibn Hudayr). There is
no fighting against the ruler in the Sunnah. It causes destruction of
the Religion and the worldy affairs." Sharh-us-Sunnah, (p. 43).
Abu Bakr al-Aajurree (d.360H) said in ash-Sharee'ah (p. 28),
"It is not fitting for the one who sees the uprising of a khaarijee
who has revolted against the Imaam, whether he is just or oppressive
- so this person has revolted and gathered a group behind him, has
pulled out his sword and has made lawful the killing of Muslims - it
is not fitting for the one who sees this, that he becomes deceived by
this person's recitation of the Qur'aan, the length of his standing
in the prayer, nor his constant fasting or his good and excellent
words in knowledge when (it is clear to him that) this person's way
and methodology (madhhab) is that of the Khawaarij."
And Ibn al-Qayyim (d.751H) said in Miftaah Daaris-Sa'aadah (1/119),
"And as for Imaam Maalik, then Ibn al-Qaasim said, "I heard Maalik
say, "Indeed there are a people who desire worship but squander the
knowledge (being deprived of it) so they revolt against the Ummah
of Muhammad with their swords. And if they had followed the
knowledge, then it would have prevented them from doing that."
It is authentically reported from the Messenger (sallallaahu alaihi wasallam) in the hadeeth of
'Iyaad ibn Ghunum who said, "The Messenger of Allaah s said,
"Whoever desires to advise the one with authority then he should
not do so openly, rather he should take him by the hand and take
him into seclusion (and then advise him). And if he accepts (the
advice) from him then (he has achieved his objective) and if not,
then he has fulfilled that which was a duty upon him."  Reported
by Ahmad (3/403) and Ibn Abee 'Aasim (2/521) with a saheeh isnaad.
And it is also related by Ibn Sa'ad in Tabaqaatul-Kubraa
(7/163-165): A group of Muslims came to al-Hasan al-Basree (d.110H)
seeking a verdict to rebel against al-Hajjaaj . So they said, "O
Aboo Sa'eed! What do you say about fighting this oppressor who has
unlawfully spilt blood and unlawfully taken wealth and did this and
that?" So al-Hasan said, "I hold that he should not be fought. If
this is the punishment from Allah, then you will not be able to
remove it with your swords. If this is a trial from Allaah, then be
patient until Allaah's judgment comes, and He is the best of
judges." So they left al-Hasan, disagreed with him and rebelled
against al-Hajjaaj - so al-Hajjaaj killed them all. 
About them al-Hasan used to say, "If the people had patience, when
they were being tested by their unjust ruler, it will not be long
before Allaah will give them a way out. However, they always rush
for their swords, so they are left to their swords. By Allaah! Not
even for a single day did they bring about any good."
1. Taken from "The Creed of Imaam al-Bukhaaree" Published by Salafi
Publications. Translated by Dawud Burbank and Amjad Rafiq.
2. This hadeeth has been reported from a group among the Companions and
see Sunan at-Tirmidhee (no. 2657), al-Musnad (4/80, 82 183), 'Jami'
ul-Usool (1/265) and Majma'uz-Zuwaa'id (1/137-139).
3. Reported from Ahmad and it is saheeh
4. Reported from Ibn Maajah and it is hasan.
5. Reported from Muslim
7. When changing the evil of the rulers, then this should be done by
the scholars and not openly as is mentioned by a clear hadeeth of
the Prophet, "When you wish to correct the sultan then take him
by the hand in secret and advise him." [Aquidah at-Tahawiyah]
8. He was ath-Thaqafee, and is well known. Adh-Dhahabee said in
Siyar A'laam in-Nubalaa (4/343) at the end of his biography, "We
revile him and do not love him, rather we hate him for Allaah. He
had some some good deed, but they are drowned in the ocean of his
sins, and his affair is for Allaah!"