Sayyiduna Ka'b bin Malik (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) forbade killing women and children.
Tabarani recorded it with various chains, the narrators of one of which are the narrators of the Sahih.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الجهاد / 9604