Sayyiduna Ali (may Allah be pleased with him) says: Ammar sought permission from the Prophet (peace and blessings be upon him), so the Prophet (peace and blessings be upon him) said: "Welcome to the purified, the chaste."
Hadith Referenceمعجم صغير للطبراني / كتاب المناقب / 852
Hadith Gradingمحدثین:صحيح
Hadith Takhrij«صحيح ، أخرجه ابن حبان فى «صحيحه» برقم: 7075، 7076، والحاكم فى «مستدركه» برقم: 5711، والترمذي فى «جامعه» برقم: 3798، وابن ماجه فى «سننه» برقم: 146، 147، قال الشيخ الألباني: صحيح ، وأحمد فى «مسنده» برقم: 790، 1014، والطيالسي فى «مسنده» برقم: 119، وأبو يعلى فى «مسنده» برقم: 403، 404، والطبراني فى «الأوسط» برقم: 4794، والطبراني فى «الصغير» برقم: 238، وابن أبى شيبة فى «مصنفه» برقم: 32909»
´It was narrated that 'Ali bin Abu Talib said:` "I was sitting with the Prophet, and 'Ammar bin Yasir asked permission to enter. The Prophet said: 'Let him in, welcome to the good and the purified.'"
Maulana Ataullah Sajid
(1) Hazrat Ammar, his father Yasir, and his mother Sumayyah radi Allahu anhum are among those great Companions who accepted Islam in its early period and endured many hardships at the hands of the disbelievers. Therefore, in the eyes of the Prophet sallallahu alayhi wa sallam, their status was very elevated.
(2) The meaning of "purified" is that Allah, the Exalted, granted them sincerity and cleansed them of such habits and characteristics that are not befitting of a believer with perfect faith.
(3) Welcoming and greeting friends with "marhaban" (welcome) is also included among noble manners.
Source: Commentary on Sunan Ibn Mājah by Mawlānā ‘Atā’ullāh Sājid, Page: 146