“Have you ever seen a friend putting to death a friend?”

Amir al-Mu’minin ‘Ali says that when Allah desired to take away the soul of Ibrahim He sent the Angel of death. “As salaamo A’laika Ya Ibrahim” said the Angel of death. “Wa a’laikas salaamo Ya Malakul Maut,” replied Ibrahim, “Have you come to take me towards the Hereafter or you bring the news of death? Indeed, you have come to capture my soul!”
“Yes” said the Angel, “I have come for this purpose and by your permission I invite you to meet your Lord and enter the heavenly world. So please accept this invitation.”
Ibrahim said, “Have you ever seen a friend putting to death a friend?”
The angel went back to his appointed place in the Heavens and told Allah, “My Lord you heard what your Khalil said?”
It was revealed upon him to go back to Ibrahim and ask if he had known of any friend hesitating to meet his friend? A true friend is the one was looks forward to their meeting. Upon hearing this argument, Ibrahim relented.

Reference: Hayat Al-Qulub, Vol. 1, Stories of the Prophets