Narrated Isam al-Muzani: The Messenger of Allah ﷺ sent us in a detachment and said (to us): If you see a mosque or hear a muadhdhin (calling to prayer), do not kill anyone.
Hadith Referenceسنن ابي داود / كتاب الجهاد / 2635
Hadith Gradingالألبانی:ضعيف | زبیر علی زئی:ضعيف, إسناده ضعيف, ترمذي (1549), ابن عصام : لا يعرف حاله, انوار الصحيفه، صفحه نمبر 96
Hadith Takhrij« سنن الترمذی/السیر 2 (1549)، (تحفة الأشراف: 9901)، وقد أخرجہ: مسند احمد (3/448) (ضعیف) » (اس کے راوی عبد الملک لین الحدیث، اور ابن عصام مجہول ہیں)
´Narrated Ibn 'Asim Al-Muzani:` From his father and he was a Companion who said: "When the Messenger of Allah (ﷺ) dispatched any army or battalion, he would say to them: 'If you see a Masjid, or hear someone calling the Adhan, then do not kill anyone.'"
Shaykh Dr. Abdur Rahman Freywai
Explanation: 1: That is, when any sign or symbol of Islam becomes apparent, then do not attack until the distinction between believer and disbeliever becomes clear.
Note: (In the chain of narration, "Abdul Malik bin Nufal" is weak in hadith, and "Ibn ‘Isam" is an unknown narrator.)
Source: Sunan al-Tirmidhi – Majlis ‘Ilmi Dar al-Da‘wah, New Delhi Edition, Page: 1549