In the name of Allah, Most Gracious, Most Merciful
Assalaamu `alaykum waRahmatullahi Wabarakatoh
The narration mentioned in the query is related as follows:
عن المهلب بن أبى صفرة قال أخبرنى من سمع النبى صلى الله عليه وسلم يقول « إن بيتم فليكن شعاركم حم لا ينصرون ».
It has been narrated in Sunan Abi Dawood on the authority of Muhallab bin Abi Safrah (Rahimahullah) that he narrates from those who have heard from Nabi (Sallallahu Alaihi Wasallam) that Nabi (Sallallahu Alaihi Wasallam) said, “When you are being attacked at night, your slogan should be ‘Hameem La Yunsaroon’.
It has been explained in Ta’leequl Mahmood, on the marginal notes of Sunan Abi Dawood, that by reading these words, one takes a vow upon Alah Ta’ala that the enemy will not be assisted. It is as if though one is trying to attain the help of allah Ta’ala.
Sunan Abi Dawood Vol.1 Pg.349 (H.M. Sa’eed Company)
This phrase was used as a slogan amongst the Muslims. When they were attacked at night, they would utter this phrase so that the other Muslims are informed that they are being attacked.
This phrase also served as a secret code to identify with fellow Muslims. A non-Muslim may claim to be a Muslim for various reasons. If he does not forward the secret code, it will be clear that he is not a Muslim. As it has been explained on the marginal notes of Jami’ Al Tirmizi that the word شعار (shi’aar) refers to a code through which one can identify his fellow companions.
Jami’ Al Tirmizi Vol.1 Pg.297 (H.M. Sa’eed Company)
Imam Abu Dawood did not comment on this narration, which means that this is not from those narrations that are dha’eef (weak) or maudhoo’ (fabricated).
Moreover, it has been considered in Mustadrak Al Hakim as saheeh (authentic).
And Allah knows best
Wassalam
Ml. Abu Yahya,
Student Darul Iftaa
Checked and Approved by:
Mufti Ebrahim Desai
Darul Iftaa, Madrassah In’aamiyyah