Musnad Ahmad 1013:8

Sufyan narrated to us, from al-Zuhri, who heard Sahl ibn Sa’d, who witnessed the Prophet, may God bless him and grant him peace, regarding the two who engaged in *li’an* (mutual cursing). They engaged in *li’an* during the time of the Messenger of God, may God bless him and grant him peace, and I was fifteen years old. He said: "O Messenger of God, if I keep her, I have lied against her." He said: "So she brought him [the child] to the one whom he [the husband] disliked."