Narrated Anas ibn Malik: The Prophet ﷺ said: Go in Allah's name, trusting in Allah, and adhering to the religion of Allah's Messenger. Do not kill a decrepit old man, o a young infant, or a child, or a woman; do not be dishonest about booty, but collect your spoils, do right and act well, for Allah loves those who do well.
Hadith Referenceسنن ابي داود / كتاب الجهاد / 2614
Hadith Gradingالألبانی:ضعيف | زبیر علی زئی:ضعيف, إسناده ضعيف, خالد بن الفرز ضعفه ابن معين وغيره ولم يوثقه غير ابن حبان فھو : مجهول أو ضعيف, انظرالتحرير (1665), انوار الصحيفه، صفحه نمبر 95
Hadith Takhrij« تفرد بہ أبو داود، (تحفة الأشراف: 824) (ضعیف) » (اس کے راوی خالد بن فزر لین الحدیث ہیں)
Benefits and Issues: It is not permissible to kill an elderly person in battle. Except for such elderly people about whom it is known that they give plans and strategies. And such women who are involved in matters like espionage, etc. It will be permissible to kill them.
Source: Sunan Abu Dawood – Commentary by Shaykh Umar Farooq Saeedi, Page: 2614