Jamiat Tirmidhi: Hadith 1753

"The Prophet (ﷺ) sent two armies, place 'Ali bin Abi Talib as the commanded of one of them, and Khalid bin Al-Walid over the other. He said: 'Where there is fighting, then 'Ali (is in command).'" He said: "So 'Ali conquered a fortress and took a slave girl. Khalid [bin Al-Walid] wrote a letter and sent me with it to the Prophet (ﷺ), to speak against him for it. So I arrived to the Prophet (ﷺ) to read the letter. The color of his face changed, the he said: 'What do you think about a man who loves Allah and His Messenger, and Allah and His Messenger love him?'" He said: "I said: 'I seek refuge from angering Allah and angering His Messenger, I am only the Messenger.' So he was silent.

[Abu 'Eisa said:] There is something about this from Ibn 'Umar. This Hadith is Hasan Gharib, we do not know of it except from the narration of Al-Ahwas bin Jawwab. And his saying: "To speak against him for that." refers to An-Namimah.