Musnad Ahmad 30:1161

'Ali ibn Hafs narrated to us, Warqa' informed us, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "While two women were with their two sons, a wolf came and took one of the two sons. They sought judgment from David, and he judged that the child belonged to the elder woman. They went out, and Solomon called them and said: 'Bring me a knife; I will split him between them.' The younger woman said: 'May Allah have mercy on you, he is her son, do not split him.' So he judged that the child belonged to the younger woman." Abu Hurayrah said: "By Allah, we did not know what a *sikkin* (knife) was until that day, and we used to call it nothing but *al-mudyah*."