Hadith 1:

مُحَمَّدُ بْنُ يَحْيَى عَنْ أَحْمَدَ بْنِ مُحَمَّدٍ عَنْ عَلِيِّ بْنِ النُّعْمَانِ عَنِ ابْنِ مُسْكَانَ عَنِ الْحَسَنِ الصَّيْقَلِ قَالَ سَمِعْتُ أَبَا عَبْدِ اللَّهِ (عليه السلام) يَقُولُ إِنَّ وَلِيَّ عَلِيٍّ (عليه السلام) لَا يَأْكُلُ إِلَّا الْحَلَالَ لِأَنَّ صَاحِبَهُ كَانَ كَذَلِكَ وَ إِنَّ وَلِيَّ عُثْمَانَ لَا يُبَالِي أَ حَلَالًا أَكَلَ أَوْ حَرَاماً لِأَنَّ صَاحِبَهُ كَذَلِكَ

Narrated that Abu Abd-Allah Imam Sadiq (عليله السلام) said,

"Indeed the friend of Ali (عليه السلام) will not eat but what is permissible (Halal) because his Master was like that. And the friend of Usman does not care if he eats the permissible (Halal) or the prohibited (Haram) since his master was like that."

(partial hadith quoted here)

[Source: al-Kafi, Vol. 8, Pg. 163]

Hadith 2:

وذكر الثقفي في تاريخه عن أبي سعيد التيمي، قال: سمعت عليا عليه السلام يقول: أنا يعسوب المؤمنين وعثمان يعسوب الكافرين

Al-Saqafi in his Tareek stated, from Abi Saeed al-Taimi, who said. I heard Ali (as) say, "I am the leader of the believers while Usman is the leader of the disbelievers."

[Source: Bihar al-Anwar, Vol. 31, Pg. 307 & Taqreeb al-Ma'arif - Sheikh Abu Saleh Taqi bin Najm al-Hilli (374-447 Hirji) , Pg. 293]

Hadith 3:

وذكر الثقفي عن هبيرة بن مريم، قال: كنا جلوسا عند علي عليه السلام، فدعا ابنه عثمان، فقال له: يا عثمان ! ثم قال: إني لم أسمه باسم عثمان الشيخ الكافر، إنما سميته باسم عثمان بن مظعون

Al-Saqafi in his Tareek stated, from Habeerah bin Maryam who said,

"We were seated with Ali (as) when he called His son Usman and said, "O' Usman". Then He said, "I did not name him after Usman the chief of the disbelievers, verily I named him after Usman bin Mazoon."

[Source: Bihar al-Anwar, Vol. 31, Pg. 307 & Al-lahoof, Pg. 149 & Taqreeb al-Ma'arif - Sheikh Abu Saleh Taqi bin Najm al-Hilli (374-447 Hirji) , Pg. 294]