Man Lā Yahduruhu al-Faqih: And he narrated in al-Faqih with what was recited by al-Fadhl – meaning al-Fadhl bin Shādhān – from the reasons:

From al-Ridha عليه السلام, who said: People were ordered to recite [the Qur’ān] in prayers, lest the Qur’ān would become abandoned and lost, and so that it is preserved and studied, so it is not effaced and ignored. It only started with al-Hamd in preference to the rest of the chapters, because there is nothing from the Qur’ān and speech in which has gathered together the whole of good and wisdom, like which what has been gathered in Ṣūrat al-Ḥamd; and that is His, Mighty and Majestic, statement: [All] praise is [due] to Allah and that is the fulfillment for what Allāh, Mighty and Majestic, has made obligatory upon the creations in giving thanks, and giving thanks is in conjunction with the goodness of what He has blessed his servant with.
Lord of the worlds – [is the] Oneness and praise of Him, and the confession that He is the Creator & Sovereign, and no one else.
The Entirely Merciful, the Especially Merciful – [is the] imploring of Him, and remembrance His Favours and His Blessings upon all of His creations.
Sovereign of the Day of Recompense – [is the] acceptance to Him of the ressurection, reckoning, recompensing, and the affirmation that he is the sovereign of the hereafter is His, just as the affirmation the sovereignty of this worldly life.
It is You we worship – [is the] aspiration and nearness to Allāh, Elevated is His mention, and sincerity to Him – and no other – in action.
And You we ask for help – [is the] desire for the increase in His attunement, His worship, and the longevity of what He has bestowed upon him and aided him.
Guide us to the straight path – [is the] guidance to His religion, and the clinging onto His rope, and the desire for increase in cognizance of his Lord, Mighty and Majestic, and His Magnificence and Grandeur.
The path of those upon whom You have bestowed favour – [is the] assertion of asking and desiring, and remembrance of what is to come from the bounties bestowed upon His friends, and desire for the like of such bounties.
Not of those who have evoked [Your] anger – [is the] seeking refuge from becoming of the hardheaded or the disbelievers, [those that] belittle Him and His commands and His prohibitions.
Or of those who are astray – [is the] seeking of protection from being of those who stray from the path without percieving, while they consider that are doing good.
Therefore, within it (Ṣūrat al-Ḥamd) was gathered the whole of good and wisdom, from the affairs of the hereafter and this worldly life, which no other thing can gather.

وروى في ( الفقيه ) فيما ذكر الفضل – يعني الفضل بن شاذان – من العلل عن الرضا ( عليه السلام ) أنه قال : « أمر الناس بالقراءة في الصلاة ، لئلا يكون القرآن مهجورا مضيعا ، وليكون محفوظا مدروسا ، فلا يضمحل ولا يجهل . وإنما بدأ بالحمد دون سائر السور ، لأنه ليس شيء من القرآن والكلام جمع فيه من جوامع الخير والحكمة ما جمع في سورة الحمد ، وذلك أن قوله عز وجل : * ( الْحَمْدُ لِلَّه ) * هو أداء لما أوجب الله عز وجل على خلقه من الشكر ، والشكر لما وفق عبده من الخير . * ( رَبِّ الْعالَمِينَ ) * توحيد وتمحيد له ، وإقرار بأنه الخالق المالك لا غيره . * ( الرَّحْمنِ الرَّحِيمِ ) * استعطافه وذكر آلائه ونعمائه على جميع خلقه . * ( مالِكِ يَوْمِ الدِّينِ ) * إقرار له بالبعث ، والحساب ، والمجازاة ، وإيجاب ملك الآخرة له ، كإيجاب ملك الدنيا . * ( إِيَّاكَ نَعْبُدُ ) * رغبة وتقرب إلى الله تعالى ذكره ، وإخلاص له بالعمل دون غيره . * ( وإِيَّاكَ نَسْتَعِينُ ) * استزادة من توفيقه ، وعبادته ، واستدامة لما أنعم عليه ونصره . * ( اهْدِنَا الصِّراطَ الْمُسْتَقِيمَ ) * استرشاد لدينه ، واعتصام بحبله ، واستزادة في المعرفة لربه عز وجل وكبريائه وعظمته . * ( صِراطَ الَّذِينَ أَنْعَمْتَ عَلَيْهِمْ ) * تأكيد في السؤل والرغبة ، وذكر لما قد تقدم من نعمه على أوليائه ، ورغبة في مثل تلك النعم . * ( غَيْرِ الْمَغْضُوبِ عَلَيْهِمْ ) * استعاذة من أن يكون من المعاندين الكافرين ، المستخفين به وبأمره ونهيه . * ( ولَا الضَّالِّينَ ) * اعتصام من أن يكون من الذين ضلوا عن سبيله من غير معرفة ، وهم يحسبون أنهم يحسنون صنعا . وقد اجتمع فيها من جوامع الخير والحكمة ، من أمر الآخرة والدنيا ، ما لا يجمعه شيء من الأشياء » .