A beautiful and authentic hadith by Imam al-Sadiq (as) describing the condition and status of the Imams (as):

“Abu ‘Abd Allah (as) describing the condition of ‘A’immah (as) and their attributes in one of his sermons has said, ‘Allah, the Most Holy, the Most High, has explained His religion through ‘A’immah of (true) guidance from the family of our Prophet (sawa) the Ahl al-Bayt (as) and has cleared through them the path of His system and plan. He has opened through them the inside of the springs of His knowledge. Whoever of the followers of Muhammad (sawa) has recognized his obligation toward the rights of his Imam he has realized the taste of the sweetness of his belief and the superior beauty of his Islam. It is because Allah, the Most Holy, the Most High, has appointed the Imam as torchbearer for His creatures and authority over those who receive His blessings in His world. He has crowned him with dignity and has encompassed him in the light of His Omnipotence that extends for him a means to the heavens. He does not discontinue His blessings for him. None of the things with Allah is achieved except through its right means. Allah does not accept the good deeds of His servants without their recognition of the Imam (as). The Imam (as) knows how to sort out the dark confusing matters and things that may obscure the Sunnah (tradition of the Holy Prophet (sawa)) and the confounding matters in mischievous conditions. Allah, the Most Holy, the Most High, has always chosen ‘A’immah from the descendents of al-Husayn (as) one after the other Imam. He would select and choose them for the leadership of His creatures delightfully and well satisfied with them. Whenever one Imam would leave this world He would appoint for His creatures his successor as a clear beacon and a shining guide, a guarding leader, and a knowledgeable one with Divine Authority. ‘A’immah from Allah guide people with the truth and with the truth they judge. They are Allah’s authority calling people to Him, and shepherds of His creatures. With their guidance people follow the religion and from them the land receive light. Through their holiness the bounties increase. Allah has made them life for the people and the torches in the darkness, the keys to communication and the strongholds for Islam. Thus, have the measures of Allah continued in them toward His final decision.
“The Imam (as) is the outstanding amicable one; the most trusted guide and the guardian who can make hopes come true. Allah has chosen him with such distinctions. He selected him as such (well protected) in the realm when all things were in the form of particles in the instant that He made him. He chose him as such (well-protected) in the realm in which all things were designed as He had designed him as a shadow, before He made the organisms, on the right side of His throne, gifted him with wisdom in the unseen knowledge with Him. He chose him in His knowledge and granted him outstanding nobility for his purity.
“He is an heir of Adam, the best one among the descendents of Noah, the chosen one of the family of Abraham, a descendent of Ishmael and of the most preferred ones in the family of Prophet Muhammad (sawa), He has always been looked after by the watchful eyes of Allah Who provides him security and guards him with His shield, well protected against the evil nets of Satan and his armies. He is well defended against the approaching dark nights and the false accusations of the evildoers. All wickedness is kept away from him and he is kept safe against all forms of defects and flaws. He is veiled against all scourges.
“He is infallible in matters of sins. He is kept safe and sound against all indecencies. He is well known for his forbearance and virtuousness in the early days of his life. Chastity, great knowledge and excellence are ascribed to him toward the end of his life. The task of Imamat (Leadership with Divine Authority) of his father rests with him while in the lifetime of his father he remains silent.
“When the time of the Imamat of his father ends it is the time when the measure of Allah ends up with him due to His wish. The will of Allah brings him to His love, thus, the end of the Imamat of his father comes and he passes away. The Authority from Allah shifts to him after his father. He then is made the person in charge of His religion, the Divine Authority over His servants, the guardian over His lands, he is supported with His spirit and is given of His knowledge. He raises him as a beacon for His creatures, makes him to have His Authority over the people of his world and as the light for the people of His religion and a guardian for His servants. Allah agrees to have him as Imam of the people, entrusts him with His secret, makes him a safe keeper of His knowledge and hides His wisdom in him. He protects him for His religion, calls upon him to serve His great task, and revives through him the phases of His system (of religion) and the obligations in His laws.
“The Imam then enforces justice – when the people of ignorance are confused and the disputing and quarrelling people are frustrated – with shining light, the beneficial cure and radiant truth. He does so with clear explanations of all aspects and exactly in the manner and practice his truthful father and forefathers would do before him. No one ignores the rights of such a scholar except the wicked ones. No one refuses and denies him except those who have strayed away from the right path. No one keeps away from him except those who are aggressive against Allah, the Most Holy, the Most High.”

Sanad: Muhammad ibn Yahya has narrated from Ahmad ibn Muhammad ibn ‘Isa from al-Hassan ibn Mahbub from Ishaq ibn Ghalib who has said the above hadith

Source: Usool al-Kafi, Volume 1, Chapter 72, Hadith #2 (See Image 1 below)

Grading: Allaamah al-Majlisi (rh) says this hadith is Authentic/Sahih (صحيح) [Mira’at al-Uqool, Volume 2, Page 400 (See Image 2 below)]