Sayyiduna Ammar bin Yasir (may Allah be pleased with him) asked Sayyiduna Ali (may Allah be pleased with him) about taking the offspring of the people of the Camel captive. Sayyiduna Ali (may Allah be pleased with him) replied: There is no taking captive for them; we only fought those who fought us. (Sayyiduna Ammar (may Allah be pleased with him)) said: Had you said anything other than this, I would have opposed you.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16749