Sayyiduna Sa'd bin Zayd al-Ashhali (may Allah be pleased with him) said: A sword from Najran was presented as a gift to the Prophet (peace and blessings be upon him). When it reached him (peace and blessings be upon him), he (peace and blessings be upon him) gave it to Sayyiduna Muhammad bin Maslamah (may Allah be pleased with him) and said: "Strive (in jihad) with this in the path of Allah. Then, when people's necks turn against one another (that is, when strife and civil war break out), strike it against a rock, then stay in your house and lie there like a spread-out mat, until a sinful hand kills you or a decisive death comes to you."
Imam al-Tabarani (may Allah have mercy on him) said: "This hadith is narrated from Sayyiduna Sa'd bin Zayd (may Allah be pleased with him) only with this chain, and al-Hajabi is alone in narrating it."
Hadith Referenceالمعجم الأوسط / باب الألف / 2375
Hadith Takhrij«أخرجه الحاكم فى «المستدرك» برقم: 4631، والطبراني فى «الكبير» برقم: 5424»