The command to refrain from fighting in tribulation

It is narrated from the paternal uncle of Amr that he said: I went out with Muslim bin Uqbah. When we came level with a valley where Sayyiduna Muhammad bin Maslamah (may Allah be pleased with him) was staying, Muslim sent me to him. I asked (before going): If he refuses to come to you, what is your order? He said: "Then cut off his head and bring it to me." So I went to him and said: Respond to the summons of the amir (come with me to him). He asked: "Who is the amir?" I said: Muslim bin Uqbah. He said: "What does the amir want to do with me? I pledged allegiance on the blessed hand of the Messenger of Allah (peace and blessings be upon him) with this very hand of mine, and since then I have neither broken the covenant nor made any change (in my religion and faith)." (Hearing this) I drew my sword from its sheath and said: I will take your head to the amir. He said (with great steadfastness): "Then take it (cut off my head)." I asked: What has prompted you to this conduct? He said: The Messenger of Allah (peace and blessings be upon him) took a covenant from me and said: "When you see people pledging allegiance to two amirs, then take that sword of yours with which you fought alongside me and strike it against (Mount) Uhud until it breaks; then sit in your house until a sinful hand comes to you (to kill you) or a decreed death overtakes you."
I (Ibn Hajar) say: Imam Ahmad (may Allah have mercy on him) narrated through his chain another hadith with this meaning, but its context is not this one, nor does it contain the words "until a hand comes to you" to the end of the hadith; moreover, this chain is weak because it contains a narrator whose condition is not known.

It is narrated from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) said: "Is any of you unable, when a man comes to him intending to kill him (that is, someone from the people of the Qiblah), to be like this (silent and passive)?" Then he (peace and blessings be upon him) placed one of his hands on the other (explaining by action) and said: "So let him be like the better of the two sons of Adam (peace be upon him) (that is, Habil); in that case he will be in Paradise while his killer will be in the Fire (of Hell)."
In the chain of this hadith, Layth bin Abi Sulaym has been declared da'if (weak) because of his memory; however, this meaning of preferring to be the one killed over being the killer in times of fitnah is established by other authentic hadiths (for example, Sunan Abi Dawud: 4259), and therefore this narration is sound in terms of its meaning.