Sayyiduna Qays bin Asim (may Allah be pleased with him) said: I came to the Prophet (peace and blessings be upon him) and said: In the Jahiliyyah I buried twelve or thirteen daughters alive. So he (peace and blessings be upon him) said: "Free slaves equal to their number."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الديات / 16425