In Kitāb al-Amwāl (Book of State Revenue), Abū ‘Ubayd al-Qāsim ibn Sallām* provides us with an accurate record of legal precedents laid down in the first two centuries of Islam, in particular those pertaining to the sources of revenue and the avenues of public expenditure. The book is essential for every student of Islamic law, especially those who wish to master the art of interpreting and analyzing legal traditions and early precedents. In the discipline known as fiqh al-sunnah, there is no book or manual that can compete with this outstanding work. Its power lies in the method of the author and the analysis undertaken by him. He gathers together the traditions of the Prophet ﷺ, the opinions of his Companions and the views of eminent jurists, and then subjects them to legal analysis that is unparalleled in Islamic legal literature.
[Excerpted from the rubric on the cover of the English translation].
Below is the section at the beginning of the book which deals with the rights of the Imam (Caliph) and the reciprocal rights of the citizens. For the complete chains of narration, please refer to the Arabic text which can be viewed here:
The Right of the Imam over the Citizens and the Right of the Citizens over the Imam
- [Tamīm ibn Aws al-Dārī relates]: “The Messeger of Allah ﷺ said: ‘Dīn is sincere advice.’  It was said: ‘For Whom, O Messenger of Allah?’ He replied ‘For (the sake of ) Allah, His Messenger, His Book, the Imams, and for the Muslim community.’
- [Also related by Tamīm ibn Aws al-Dārī (with a different chain)] from the Prophet ﷺ, a similar narration, except that he repeated the words “Dīn is sincere advice” three times.
- Ibn ‘Umar relates: “The Messenger of Allah ﷺ said: ‘Each of you is a shepherd and each is responsible for his flock. The ruler over mankind is a shepherd over them and as such is responsible for them. Each man is a shepherd for the members of his family, and is responsible for them. A man’s wife is a shepherdess for her husband’s house and her children, and she is responsible for them. A man’s servant is a shepherd for his master’s property and he is responsible for it. Beware, each one of you, then, is a shepherd and each one of you will be questioned about his flock.’ ”
- From the Prophet ﷺ (is related) a similar (hadith) [with a different chain of narration].
- [‘Atā’ ibn Yasar relates that]: “A man said to the Messenger of Allah ﷺ, ‘Of all things, authority is the worst.’ The Prophet ﷺ said: ‘Of all things authority is the best for one who employs it for its lawful functions and fulfils its obligations. It is a terrible thing for one who employs it for unlawful and illegitimate ends; on the Day of Judgement he will be overcome by grief and remorse.’ ”
- From al-Ḥārith ibn Yazīd al-Ḥaḍramī: “Abū Dharr requested an office (authority) from the Messenger of Allah ﷺ. The Messenger of Allah ﷺ said to him: ‘It is a trust, (a cause of) grief and remorse on the Day of Judgement, except for one who employs it for its lawful ends and performs that which is obligatory on him through it.’ ”
- …From al-Ḥārith ibn Yazīd al-Ḥaḍramī who said: “I heard Ibn Ḥujayrah al-Shaykh as saying, ‘One who heard from Abū Dharr related to me: “I spent a night in intimate conversation with the Messenger of Allah” – or he said a night till dawn – and said, “O Messenger of Allah, grant me an office”, and he (the Prophet ﷺ) replied, “It is a trust, (a cause of) grief and remorse on the Day of Judgement, except for one who employs it rightfully and performs what is obligatory on him through it.” ’ ”
- [From ‘Urwah ibn al-Zubayr]: “Abū Bakr, may Allah be pleased with him, addressed the people. He (first) praised and glorified Allah and then said: ‘I have assumed authority over your affairs, but I am not the best of you. The Qur’an was revealed and the Prophet ﷺ established (his) Sunnah. He taught us and we acted accordingly, and we came to know – O People – that the greatest wisdom comes through guidance’ – or he said ‘fear of Allah’ – and Abu ‘Ubayd doubting this said: I believe it is taqwa (fear of Allah) – ‘and the greatest humility comes through iniquity. The weak among you is the strongest to me, till such time that I have had his rights restored, and the strong among you is the weakest till I have secured from him rights (that were usurped). O Men, I am a follower (of the Shari‘ah) but not its inventor. If I do well (in the performance of my duties), co-operate with me, but if I deviate (from the right path), correct me. With this I end my talk and beseech Allah that He may forgive you and me.’ ”
- From Abū Bakr is related a similar (narration) [with a different chain].
- [From al-Ḥasan]: “ ‘Umar wrote to Abū Mūsā (al-Ash‘arī) (saying): ‘The strength of work lies in not putting off today’s work till tomorrow. If you do so, your work will overwhelm you and you will not know which task to undertake first. Your organization will then fall apart. Verily, tasks are carried out for the ruler only when the ruler himself fulfils the obligations due to Allah. If his behaviour is unbridled, so is that of his subordinates – (and in such a case) the people develop a revulsion for their rulers – and I seek the protection of Allah against this state (or he said: lest this state overtake us) for it breeds jealousies, (leads to) the preference of worldly matters, and the pursuit of whims. So establish justice, even if it is for a brief moment in a day.’ ”
- [From Mus‘ab ibn Sa‘d ibn Abī Waqqās]: “ ‘Alī ibn Abī Ṭālib, on him be peace, affirming the truth, said: ‘It is obligatory on the Imam to adjudicate according to the commandments of Allah and to discharge the trust (reposed in him). When he does so, it is obligatory on the people to pay heed to him, to obey him and to respond to his call.’ ”
- [From Salmān]: “The (true) Caliph is one who adjudicates on the basis of the Book of Allah and who shows kindness to his citizens like the kindness of a man to his family.” On hearing this, Ka‘b al-Aḥbār said: ‘He spoke in truth.’
- [From Abū ‘Ubaydah ibn ‘Abd Allāh]: “The just Imam is one who strives to lessen the complaints made to Allah, while the tyrant Imam is one against whom the complaints to Allah are numerous.”
- [From Abu Hurayrah]: From the Prophet ﷺ, who said, “One day’s work by a just Imam among his citizens is better than a hundred years, or fifty years – with Hushaym  doubting [the word fifty] – of worship of the worshipper among his family.”
- [From Ṭalḥah ibn Muṣarrif]: “Khālid ibn al-Walīd said, ‘Do not take even three steps with the intention of assuming authority over three individuals; do not retract even from the smallest commitment that you make, and do not desire to expose the Imam of the Muslims to any danger (of insurrection).’ ”
- When Sa‘d visited Salmān (during his illness) he said to him: “Give us some advice, O Abū ‘Abd Allāh, that we may abide by it.” He said: “When you resolve to undertake some work, or are about to distribute (wealth), or are about to render a decision, remember Allah.”
 The word naṣīḥah is used in various meanings: sincerity; loyalty; advice and some other meanings. The meaning in which it is used by the jurists is that of al-amr bi’l-ma‘rūf wa nahy ‘ani’l-munkar (enjoining the good and forbidding the evil).
 He was Hushaym ibn Bashīr, one of Abu ‘Ubayd’s teachers.
[Cf. The Book of Revenue: Kitāb al-Amwāl, translated by Professor Imran Ahsan Khan Nyazee, Garnet Publishing, Reading, 2003, pp. 3 to 6]
* Abū ‘Ubayd al-Qāsim ibn Sallām al Harawī was a brilliant early scholar of Arabic grammar, lexicography, poetry, syntax, Qur’anic sciences, hadith and fiqh. In some of these fields he contributed pioneer studies of major significance. He was born in Herat, the son of a freed slave of Byzantine origin. He became well-known for his piety, learning, virtue and adherence to orthodoxy.
After first studying in his native town, in his early twenties he travelled to Kufa, Basra and Baghdad to complete his studies. Among his teachers were al-Aṣma‘ī, Abū ‘Ubayda, Abū Zayd al-Anṣārī, Abū ‘Amr al-Shaybānī, al-Kisā’ī, al-Farrā’ and many others.
Returning home, he became a tutor to two influential families in Khurasan and in 192 H/807 CE, he was appointed as the Qāḍī of Tarsus (in Cilicia) by its governor, Thabit b. Nasr b. Malik, and remained in this post for eighteen years. Later, he settled in Baghdad and in the year 219 H/834 CE he performed the Hajj. He remained in Makka till he passed away (according to al-Bukhārī) in 224 H/838 CE, being buried in the house of Ja‘far ibn Abī Tālib.
According to Abū Bakr ibn al-Anbārī: “Abū ‘Ubayd divided the night in three parts, one of them for prayer, one for sleep, and one for the composition of his works.”
And Ishāq ibn Rāhwayh said of him: “Abū ‘Ubayd surpasses us all in the (Islamic) sciences, in philological knowledge, and in the mass of information which he has collected; we stand in need of Abu ‘Ubayd, and he stands not in need of us.”
[Cf. Ibn Khallikān, Wafayāt al-A‘yān wa-Anbā’ Abnā’ az-Zamān, Vol. 2, pp. 486-489 of De Slane’s English translation (available online here)]