It is narrated from Sayyiduna Ali (may Allah be pleased with him) that once I was present in the service of the Prophet (peace and blessings be upon him), when Sayyiduna Ammar (may Allah be pleased with him) came and began to seek permission to enter. The Prophet (peace and blessings be upon him) said, "Grant him permission, welcome to the person who is pure and possesses purity."
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 779
Hadith Gradingحکم دارالسلام:إسناده صحيح، قاله أحمد شاكر