Musnad Ahmad 27:1461

Ishaq narrated to us, Malik informed me, from Nafi’, from Ibn Umar, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever emancipates a share in a slave, and he possesses wealth that reaches the price of the slave, then the slave shall be appraised at a fair value. His partners shall be given their shares, and the slave is emancipated for him. But if he does not possess that, then only that which was emancipated is emancipated."