Answered by Shaykh Amjad Rasheed
Is there a difference in the greeting “Salam `alaykum” and “As-salamu `alaykum”? Which one is better and why?
If you mean outside of the prayer, then it is permissible to renounce the word “salam” when one says, “Salamun `alayka or `alaykum” as is stated in the Tuhfa (9/225). However, saying “As-salamu” is better, as is mentioned in the Nihaya and the Mughni. Refer to Hashiyah of Shirwani (9/225).
However, if the questioner is asking about it in the prayer, during the final salams, it is not enough to merely renounce it, according to the most correct position in the Minhaj; but rather, one must add the definite article, pronouncing it as “As-salamu `alaykum”. This is against the opinion of Imam al-Rafi`I who said that it is enough to merely blame the pronunciation of “Salamun” in the prayer.
According to the relied upon position, the difference between the final salams in the prayer and salams outside of the prayer is that it has been established in rigorously authenticated hadith that he, may Allah’s peace and blessings be upon him, used to say in his final salams in the prayer, “As-salamu `alaykum” and it has not been related of him that he said, “Salamun `alaykum”.
This is opposed to the form that he used during the tashahhud, for it has come to us that he used to say, “Salamun `alaykum” in the indefinite form [without the al’] as was clarified by Imam al-Nawawi in his Sharh al-Muhadhdhab”. So upon this evidence, saying “As-salam” outside of the prayer is analogous to what has come to us about the tashahhud in terms of being in the indefinite, and Allah knows best.
الجواب : إن كان المرادُ بالسؤال لفظَ السلام خارج الصلاة فنعم يجوز تنكير لفظ السلام فيقول ( سلام عليك أو عليكم ) كما صرح به في “التحفة” (9/225) ، لكن التعريف أفضل كما في “النهاية” و”المغني” . انظر : حاشية الشرواني (9/225) .
أما إن قصد السائلُ لفظ السلام في تسليم الصلاة فلا يكفي فيه التنكير على الأصح في “المنهاج” بل لا بدّ من تعريف لفظ السلام فيقول : السلام عليكم . خلافاً للإمام الرافعي القائل بصحة تنكير لفظ سلام الصلاة .
وعلى المعتمد فالفرقُ بين سلام الصلاة وغيرها أنه ثبتت الأحاديثُ الصحيحةُ أنه صلى الله عليه وسلم كان يقول في التسليم آخر الصلاة : ( السلامُ عليكم ) ولم ينقل عنه ( سلام عليكم ) بخلاف صيغته في التشهد فقد ورد (سلامٌ عليكم ) بالتنكير كما بينه الإمام النووي في “شرح المهذب” ، وعليه فيكون السلام خارج الصلاة مقاساً على ما ورد في التشهد من التنكير ، والله أعلم .