Hadith 1:

حَدَّثَنَا الْمُظَفَّرُ بْنُ جَعْفَرِ بْنِ الْمُظَفَّرِ الْعَلَوِيُّ السَّمَرْقَنْدِيُّ رَضِيَ اللَّهُ عَنْهُ قَالَ حَدَّثَنَا جَعْفَرُ بْنُ مُحَمَّدِ بْنِ مَسْعُودٍ عَنْ أَبِيهِ قَالَ حَدَّثَنَا جَبْرَئِيلُ بْنُ أَحْمَدَ عَنْ مُوسَى بْنِ جَعْفَرٍ الْبَغْدَادِيِّ قَالَ حَدَّثَنِي الْحَسَنُ بْنُ مُحَمَّدٍ الصَّيْرَفِيُّ عَنْ حَنَانِ بْنِ سَدِيرٍ عَنْ أَبِيهِ سَدِيرِ بْنِ حُكَيْمٍ عَنْ أَبِيهِ عَنْ أَبِي سَعِيدٍ عَقِيصَا قَالَ‏ لَمَّا صَالَحَ الْحَسَنُ بْنُ عَلِيٍّ(ع) مُعَاوِيَةَ بْنَ أَبِي سُفْيَانَ دَخَلَ عَلَيْهِ النَّاسُ فَلَامَهُ بَعْضُهُمْ عَلَى بَيْعَتِهِ فَقَالَ(ع) وَيْحَكُمْ مَا تَدْرُونَ مَا عَمِلْتُ وَ اللَّهِ الَّذِي عَمِلْتُ خَيْرٌ لِشِيعَتِي مِمَّا طَلَعَتْ عَلَيْهِ الشَّمْسُ أَوْ غَرَبَتْ أَ لَا تَعْلَمُونَ أَنَّنِي إِمَامُكُمْ مُفْتَرَضُ الطَّاعَةِ عَلَيْكُمْ وَ أَحَدُ سَيِّدَيْ شَبَابِ أَهْلِ الْجَنَّةِ بِنَصٍّ مِنْ رَسُولِ اللَّهِ(ص) عَلَيَّ قَالُوا بَلَى قَالَ أَ مَا عَلِمْتُمْ أَنَّ الْخَضِرَ(ع) لَمَّا خَرَقَ السَّفِينَةَ وَ أَقَامَ الْجِدَارَ وَ قَتَلَ الْغُلَامَ كَانَ ذَلِكَ سَخَطاً لِمُوسَى بْنِ عِمْرَانَ إِذْ خَفِيَ عَلَيْهِ وَجْهُ الْحِكْمَةِ فِي ذَلِكَ وَ كَانَ ذَلِكَ عِنْدَ اللَّهِ تَعَالَى ذِكْرُهُ حِكْمَةً وَ صَوَاباً أَ مَا عَلِمْتُمْ أَنَّهُ مَا مِنَّا أَحَدٌ إِلَّا وَ يَقَعُ فِي عُنُقِهِ بَيْعَةٌ لِطَاغِيَةِ زَمَانِهِ إِلَّا الْقَائِمُ الَّذِي يُصَلِّي رُوحُ اللَّهِ عِيسَى ابْنُ مَرْيَمَ (ع) خَلْفَهُ فَإِنَّ اللَّهَ عَزَّ وَ جَلَّ يُخْفِي وِلَادَتَهُ وَ يُغَيِّبُ شَخْصَهُ لِئَلَّا يَكُونَ لِأَحَدٍ فِي عُنُقِهِ بَيْعَةٌ إِذَا خَرَجَ ذَلِكَ التَّاسِعُ مِنْ وُلْدِ أَخِي الْحُسَيْنِ بْنِ سَيِّدَةِ الْإِمَاءِ يُطِيلُ اللَّهُ عُمُرَهُ فِي غَيْبَتِهِ ثُمَّ يُظْهِرُهُ بِقُدْرَتِهِ فِي صُورَةِ شَابٍّ دُونَ أَرْبَعِينَ سَنَةً ذَلِكَ لِيُعْلَمَ‏ أَنَّ اللَّهَ عَلى‏ كُلِّ شَيْ‏ءٍ قَدِيرٌ

When Hasan bin Ali (ع) signed the peace treaty with Muawiyah some people came to him and blamed him for making peace. 

So Imam Hasan (ع) said, "Woe be on you, you don’t know what I did. By Allah whatever I have done is better for my followers (Shias) than everything upon which the sun rises and sets. Don’t you know that I am your Imam whose obedience is obligatory on you? And on the basis of the statement of the Messenger of Allah (ص) I am one of the chiefs of the youths of Paradise?"

All said: "Yes, indeed it is so." 

The Imam (ع) said, "Don’t you know that when Khizr (ع) made a hole in the boat, repaired the wall and killed a boy, Musa bin Imran (ع) did not like it since he was unaware of the wisdom behind those actions, while all those actions in the sight of Allah were based on wisdom and were correct? 

Dont you know that there is none among Us who did not have the allegiance of the tyrant ruler of his time around his neck, except for Qaim (عج), behind whom the Spirit of Allah, Isa bin Maryam (ع) will pray? Indeed, Allah, the Mighty and the Sublime has kept his birth secret and his person unseen so that when he reappears, he would not have the allegiance of anyone upon his neck. He is the ninth descendant of my brother, Husain (ع). He is the son of the best of the maidservants. The Almighty Allah will prolong his age during the occultation, then He would, through His power, make him appear as a youthful man of less than forty years of age so that it may be known that the Almighty Allah is powerful over everything."

[Source: Kamal al-Deen, Vol. 1, Ch. 29, Hadith. 2]

Hadith 2:

محمد بن يحيى، عن أحمد بن محمد، عن محمد بن سنان، عن أبي الصباح ابن عبد الحميد، عن محمد بن مسلم، عن أبي جعفر (عليه السلام) قال: والله للذي صنعه الحسن ابن علي (عليهما السلام) كان خيرا لهذه الأمة مما طلعت عليه الشمس والله لقد نزلت هذه الآية " ألم تر إلى الذين قيل لهم كفوا أيديكم وأقيموا الصلاة وآتوا الزكاة " إنما هي طاعة الامام وطلبوا القتال فلما كتب عليهم القتال مع الحسين (عليه السلام) قالوا: ربنا لم كتبت علينا القتال لولا أخرتنا إلى أجل قريب نجب دعوتك ونتبع الرسل أرادوا تأخير ذلك إلى القائم (عليه السلام).

Narrated that Abu Jafar Imam Baqir (عليه السلام) said,

By Allah (عز وجل), that which Al-Hasan ibn Ali (عليهما السلام) did (i.e. the peace treaty with Muawiyah), was better for this community than all that upon which the sun rises.

By Allah (عز وجل), this Verse was revealed - "Have you not seen those to whom it was said: Withhold your hands and establish prayer and pay the zakat" (4:77) but rather, it is the obedience to the Imam (i.e. the obedience to Imam Hasan ع who asked the people to hold back from fighting & did the peace treaty with Muawiyah), while they (the Muslims) demanded to fight.

But when fighting was prescribed for them alongside Al-Husayn (عليه السلام), they said, “Our Lord! why have You ordained fighting for us? If You would delay us from it till a near term?" (4:77), we would answer Your Call and will follow the Messengers. (14:44) – The Imam said, "They intended to delay that to the Qaim (عليه السلام)."

[Source: al-Kafi, Vol. 8, Hadith. 506]

Hadith 3:

حَدَّثَنَا عَلِيُّ بْنُ أَحْمَدَ بْنِ مُحَمَّدٍ (رحمه الله) قَالَ حَدَّثَنَا مُحَمَّدُ بْنُ مُوسَى بْنِ دَاوُدَ الدَّقَّاقُ قَالَ حَدَّثَنَا الْحَسَنُ بْنُ أَحْمَدَ بْنِ اللَّيْثِ قَالَ حَدَّثَنَا مُحَمَّدُ بْنُ حُمَيْدٍ قَالَ حَدَّثَنَا يَحْيَى بْنُ أَبِي بُكَيْرٍ قَالَ حَدَّثَنَا أَبُو الْعَلَاءِ الْخَفَّافُ عَنْ أَبِي سَعِيدٍ عَقِيصَا قَالَ قُلْتُ لِلْحَسَنِ بْنِ عَلِيِّ بْنِ أَبِي طَالِبٍ يَا ابْنَ رَسُولِ اللَّهِ لِمَ دَاهَنْتَ مُعَاوِيَةَ وَ صَالَحْتَهُ وَ قَدْ عَلِمْتَ أَنَّ الْحَقَّ لَكَ دُونَهُ وَ أَنَّ مُعَاوِيَةَ ضَالٌّ بَاغٍ فَقَالَ يَا أَبَا سَعِيدٍ أَ لَسْتُ حُجَّةَ اللَّهِ تَعَالَى ذِكْرُهُ عَلَى خَلْقِهِ وَ إِمَاماً عَلَيْهِمْ بَعْدَ أَبِي (ع) قُلْتُ بَلَى قَالَ أَ لَسْتُ الَّذِي قَالَ رَسُولُ اللَّهِ (ص) لِي وَ لِأَخِي الْحَسَنُ وَ الْحُسَيْنُ إِمَامَانِ قَامَا أَوْ قَعَدَا قُلْتُ بَلَى- قَالَ فَأَنَا إِذَنْ إِمَامٌ لَوْ قُمْتُ وَ أَنَا إِمَامٌ إِذْ لَوْ قَعَدْتُ يَا أَبَا سَعِيدٍ عِلَّةُ مُصَالَحَتِي لِمُعَاوِيَةَ عِلَّةُ مُصَالَحَةِ رَسُولِ اللَّهِ (ص) لِبَنِي ضَمْرَةَ وَ بَنِي أَشْجَعَ وَ لِأَهْلِ مَكَّةَ حِينَ انْصَرَفَ مِنَ الْحُدَيْبِيَةِ أُولَئِكَ كُفَّارٌ بِالتَّنْزِيلِ وَ مُعَاوِيَةُ وَ أَصْحَابُهُ كُفَّارٌ بِالتَّأْوِيلِ يَا أَبَا سَعِيدٍ إِذَا كُنْتُ إِمَاماً مِنْ قِبَلِ اللَّهِ تَعَالَى ذِكْرُهُ لَمْ يَجِبْ أَنْ يُسَفَّهَ رَأْيِي فِيمَا أَتَيْتُهُ مِنْ مُهَادَنَةٍ أَوْ مُحَارَبَةٍ وَ إِنْ كَانَ وَجْهُ الْحِكْمَةِ فِيمَا أَتَيْتُهُ مُلْتَبِساً أَ لَا تَرَى الْخَضِرَ (ع) لَمَّا خَرَقَ السَّفِينَةَ وَ قَتَلَ الْغُلَامَ وَ أَقَامَ الْجِدَارَ سَخِطَ مُوسَى (ع) فِعْلَهُ لِاشْتِبَاهِ وَجْهِ الْحِكْمَةِ عَلَيْهِ حَتَّى أَخْبَرَهُ فَرَضِيَ هَكَذَا أَنَا سَخِطْتُمْ عَلَيَّ بِجَهْلِكُمْ بِوَجْهِ الْحِكْمَةِ فِيهِ وَ لَوْ لَا مَا أَتَيْتُ لَمَا تُرِكَ مِنْ شِيعَتِنَا عَلَى وَجْهِ الْأَرْضِ أَحَدٌ إِلَّا قُتِلَ

Narrated from Abu Saeed Aqisa, who said,

I said to Hasan ibn Ali ibn Abi Talib (عليهما السلام), "O son of the Messenger of Allah (ص), why did you reconcile with Muawiyah and make peace with him when you knew that the right was with you and that Muawiyah was misguided and a transgressor?" 

Imam Hasan (عليه السلام) said, "O Abu Saeed, am I not the proof of Allah upon His creation and an Imam over them after my father?" 

I (the narrator) said, "Yes." 

The Imam said, "Am I not the one whom the Messenger of Allah (ص) said to me and my brother - Hasan and Husayn (عليهما السلام), 'They are Imams, whether they stand (rise) or sit'?" 

I (the narrator) said, "Yes." 

The Imam said, "Then I am an Imam if I stand, and I am an Imam if I sit, O Abu Saeed. The reason for my reconciliation with Muawiyah is the same reason for the Messenger of Allah's reconciliation with the tribe of Dhamra and the tribe of Ashja and the people of Mecca when he returned from Hudaybiyyah. Those were disbelievers in the revelation (of the Quran), while Muawiyah and his companions are disbelievers in the interpretation (of the Quran).

O Abu Saeed. If I am an Imam appointed by Allah, then my opinion should not be discredited in what I do, whether it is reconciliation or fighting, even if the wisdom behind what I do is unclear. 

Do you not see how Khizr (ع), when he made a hole in the ship, killed the boy, and repaired the wall, Prophet Musa (ع) was angry with his actions because the wisdom behind it was unclear to him, until he informed him, and then he was satisfied? Likewise, you are angry with me because of your ignorance of the wisdom behind it. And if I had not done what I did, not one of our followers (Shia) would have been left on the face of the earth but would have been killed."

[Source: Ilal al-Sharaie, Shaikh Sadooq, Vol. 1, Pg. 211]