How do I know if a hadith is authentic?

"Sa'id thought to himself that he would test Hasan to see if al-Hajjaj's presence would cause Hasan to speak more to endear himself or speak less out of awe. However, Hasan spoke as he always did until he concluded. When Hasan finished, indifferent to al-Hajjaj’s presence, al-Hajjaj raised his hand, struck Hasan’s shoulder, and said, 'The Sheikh is truthful and virtuous."

"but when his brother is sent to fight, he goes hungry and on foot. Hasan did not relent in his criticism until he had reminded them of their gravest and most severe faults. A man from Syria who was sitting with Hasan then went to al-Hajjaj and reported Hasan's words to him. It was not long before emissaries from al-Hajjaj came to Hasan and said, "The governor summons you."

"Sa'id continued, 'I also moved aside, leaving space for al-Hajjaj to sit. Al-Hajjaj sat between me and Hasan.' Hasan continued speaking as usual, without interruption. Sa'id thought to himself that he would test Hasan to see if al-Hajjaj's presence would cause Hasan to speak more to endear himself or speak less out of awe."

"It was not long before emissaries from al-Hajjaj came to Hasan and said, "The governor summons you. Hasan stood up, and we grew anxious for him due to the severity of his words. However, Hasan shortly returned to his seat, smiling, for he rarely did so with his mouth open in laughter, usually just smiling. He addressed us and magnified the trust, saying, "You sit with us in trust, as if you suppose that betrayal exists only in dinars and dirhams."

"and peace with them, then it is good. Otherwise, it is advised for him to consider replacing them. Ali, may Allah be pleased with him, married seven nights after the passing of Fatima, peace be upon her. It is said that Hasan ibn Ali was known for having many marriages, with over two hundred wives. He sometimes married four at once and divorced four at once, then replaced them. The Prophet, Peace be upon him, said to Hasan, You resemble my disposition and character. The Prophet also said, Hasan is from me and Husayn is from Ali. Hasan's numerous marriages were seen as resembling"

"What prevents you from spending time with people? He replied, "A matter keeps me busy from the people. Al-Hasan asked, "What prevents you from coming to this man called Al-Hasan and sitting with him? The man answered, "A matter keeps me busy from the people and from Al-Hasan. Al-Hasan then inquired, "What is this preoccupation, may Allah have mercy on you?"

"Al-Hasan once passed by a young man laughing among a group. Al-Hasan asked him, "Young man, have you crossed the path? He replied, "No. Al-Hasan asked, "Do you know whether you will end up in Paradise or Hell? He replied, "No. Al-Hasan said, "Then why do you laugh? Afterward, the young man was never seen laughing again."

"them to your son David? So Adam denied, and thus his offspring denied. Adam forgot, and thus his offspring forgot. Adam made a mistake, and thus his offspring made mistakes. This is a Hasan Sahih hadith. It has been narrated from different angles, from Abu Huraira, from the Prophet, peace be upon him. Al-Hakim also narrated it in his Al-Mustadrak, stating it is sahih according to the criteria of Muslim, though it was not included. Ibn Abi Hatim narrated from Abdurrahman ibn Zayd ibn Islam, from his father, from Atta ibn Yasir, from Abu Huraira, in an elevated form."

"The Almighty's statement, and the sun runs on a fixed course for it, that is the decree of the Almighty, the All-Knowing, further supports this understanding. This hadith is narrated in various collections, including Sahih Muslim and others, with similar wording. Al-Tirmidhi classified it as Hasan Sahih. The hadith in question does not contradict the idea of the rotation of the heavenly spheres, which are the heavens, according to the most well-known opinion."

"If not, permission must be sought first before entering. Muhammad ibn Wasi’ and his companions used to enter Al-Hasan's residence and eat what they found without permission. Al-Hasan would enter, see what they did, become pleased, and say, "This is how we were." It is narrated from Al-Hasan, may Allah be pleased with him, that he was standing eating from the wares of a merchant in the market, taking a date from one basket and a fig from another."