It was narrated to us by Moammed bin al-Qāsim, who said – it was narrated to us by Yūsif bin Moammed bin Ziyād, and ʿAlī ibn Moammed bin Yasār, from Abū Yahmā, from al-assan bin ʿAlī bin Moammed bin ʿAlī bin Mūsa bin Jaʿfar bin Moammed bin ʿAlī bin al-ussain bin ʿAlī bin Abī Tālib عليهم السلام, from his father, from his forefather عليهم السلام, who said:

One day, The Messenger of Allāh صلى الله الله عليه وآله said to one of his companions: “Oh Servant of Allāh, love for the sake of Allāh, and hate for the sake of Allāh, and befriend for the sake of Allāh, and foster enmity for the sake of Allāh – for the guardianship of Allāh does is not reached except through that, nor will a man find the taste of belief (‘imān) even with the abundance of prayers and fasting, until he has that. Nowadays, brotherhood has become mostly for the sake of the worldly life. They love for its sake and hate for its sake. They will not gain any benefit from it from Allāh.”
So he said to him: “And how will I know if I have loved and harboured enmity for the sake of Allāh? Who is the friend of Allāh so that I befriend him, and who is his enemy so that I foster enmity for him?”
The Messenger of Allāh صلى الله الله عليه وآله pointed to ʿAlī عليه السلام and said: “Do you see him?” He said: “Yes.”
He said: “A friend of him is a friend of Allāh, so befriend him; and his enemy is the enemy of Allāh, so harbour enmity for him (the enemy). Befriend the friend of his even if it is the killer of father and son, and harbour enmity for his enemy even if it were your father and son.

حدثنا محمد بن القاسم، قال: حدثنا يوسف بن محمد بن زياد وعلي ابن محمد بن يسار، عن أبو يهما، عن الحسن بن علي بن محمد بن علي بن موسى بن جعفر بن محمد بن علي بن الحسين بن علي بن أبي طالب (عليهم السلام)، عن أبيه، عن آبائه (عليهم السلام)، قال: قال رسول الله (صلى الله الله عليه وآله) لبعض أصحابه ذات يوم: يا عبد الله، أحبب في الله وأبغض في الله، ووال في الله، وعاد في الله، فإنه لا تنال ولاية الله إلا بذلك، ولا يجد رجل طعم الايمان وإن كثرت صلاته وصيامه حتى يكون كذلك، وقد صارت مؤاخاة الناس يومكم هذا أكثرها في الدنيا، عليها يتوادون، وعليها يتباغضون، وذلك لا يغني عنهم من الله شيئا. فقال له: وكيف لي أن أعلم أني قد واليت وعاديت في الله عز وجل، فمن ولي الله عز وجل حتى أو إليه، ومن عدوه حتى أعاديه؟ فأشار له رسول الله (صلى الله عليه وآله) إلى علي (عليه السلام)، وقال: أترى هذا؟ فقال: بلى. قال: ولي هذا ولي الله فواله، وعدو هذا عدو الله فعاده، وال ولي هذا ولو أنه قاتل أبيك وولدك، وعاد عدو هذا ولو أنه أبوك وولدك