روي أن رسول الله صلى الله عليه وسلم قال لقريش: إن هذا الأمر فيكم وأنتم ولاته ما لم تحدثوا عملا ينزعه الله منكم، فإذا فعلتم ذلك سلط الله عليكم شرار خلقه فالتحوكم كما يلتحي القضيب.
It is narrated that the Prophet (pbuh) said to the Quraish, "This matter [of rule] shall remain among you1 and you shall remain in charge of it till you are not guilty of any such behavior that deprives you of [the support of] God.2 When you are guilty of such behavior then God shall impose upon you the worst of His creations,3 which will tear you apart just as a stick is torn apart.4"
As is explained in an earlier narrative, the Quraish have been pointed out by the Prophet (pbuh) as those deserving of the responsibility of political rule on the basis of the fact that they are the only ones who enjoy the confidence of the other tribes of the Banu Ishmael. Thus, the Prophet (pbuh), as an application of the Qur'anic principle of "أمرهم شورى بينهم" (i.e., 'their affairs are managed through mutual consultation'), informed the people that after his demise, the political rule of the Banu Ishmael should be given to the Quraish.
i.e., the Quraish enjoy this position as a special blessing of God and God shall continue to grant them this blessing as long as they remain obedient to the laws of God.
i.e., a cruel people.
Being subject to the laws of God relating to the nation selected as a witness of God's justice, the Quraish - as the leaders of the Banu Ishmael - like the Banu Israel, shall flourish and gain strength as long as their allegiance remains with God. However, if they deviate from God's path, then God shall not just dethrone them from this position, but shall also punish them through other people.
Notes on the Text of the Narrative:
The narrative has been reported with some variations in Ahmad ibn Hanbal's narrative no. 17110, 22409 and 22415, Ibn Abi Shaibah's narrative no. 37718, Abd al-Razzaq's narrative no. 19903 and Bayhaqiy's narrative no. 16312 and 16323. Except where otherwise specified, the selected words have been reported in Ibn Abi Shaibah's narrative no. 37718.
In some narratives, as for instance in Ahmad ibn Hanbal's narrative no. 22409, the words "إن هذا الأمر فيكم" (i.e., 'This matter [of rule] shall remain among you') have been reported as "إن هذا الأمر لا يزال فيكم" (i.e., 'This matter [of rule] shall continue among you').
In some narratives, as for instance Ahmad ibn Hanbal's narrative no. 17110, the words "ما لم تحدثوا عملا" (i.e., 'till you are not guilty of any such behavior') have been reported as "ولن يزال فيكم حتى تحدثوا أعمالا" (i.e., 'And it shall continue to be in you till you are guilty of such behaviors').
In some narratives, as for instance in Ahmad ibn Hanbal's narrative no. 17110, the word "سلط" (i.e., 'impose') has been replaced with "بعث" (i.e., 'raise').
In some narratives, as for instance in Ahmad ibn Hanbal's narrative no. 17110, the words "فالتحوكم" (i.e., 'who will completely skin you') have been replaced with its present/future tense "فيلتحيكم".
In Bayhaqiy's narrative no. 16323, the Prophet (pbuh) is reported to have said:
أنتم أولى الناس بهذا الأمر ما كنتم مع الحق إلا أن تعدلوا عنه فتلحون كما تلحى هذه الجريدة يشير إلى جريدة بيده.
You are most deserving of all the people [of Banu Ishmael] of this affair [of rule], as long as you remain with what is right. Except that you stray away from it, then you shall be torn apart just as this letter is torn apart. He said this while pointing to a letter in his hand.
According to Abd al-Razzaq's narrative no. 19903, it is reported:
روي أن النبي صلى الله عليه وسلم مر بنفر من قريش ووجوههم كأنها سبائك الذهب فجعل يوصيهم فقال إنكم لن تزالوا بخير ما أتقيتم الله وحفظتم أمره من ترك ذلك منكم لحاه الله كما لحا هذا العود وجعل النبي صلى الله عليه وسلم يلحو عودا كان في يده لم يترك فيه شيئا.
It is narrated that the Prophet (pbuh) passed by a group of the people of Quraish, with faces like blocks of gold. He admonished them saying: You shall continue to enjoy affluence as long as you fear God and keep up His commandments. But whoever from among you turns away from it then God shall tear him apart, just like this stick. Then the Prophet (pbuh) started breaking a stick that was in his hand, till nothing was left of it.
(This write-up is prepared by the Hadith Cell of Javed Ahmad Ghamidi)
 The Banu Israel were also subjected to the same law and were also given the same warning, as the Quraish have been warned here. See: Al-Israa 17: 4 - 8.