Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates: Sayyiduna Umar (may Allah be pleased with him) came to Sayyiduna Salman al-Farisi (may Allah be pleased with him), and he placed a cushion for him. Sayyiduna Umar (may Allah be pleased with him) asked: "O Abu Abdullah, what is the reason for this?" Sayyiduna Salman al-Farisi (may Allah be pleased with him) said: I heard the Prophet (peace and blessings be upon him) say: "Any Muslim whose Muslim brother comes to him, and he places a cushion for him out of respect and reverence for him, Allah Almighty forgives that person."
Imam al-Tabarani recorded it in al-Mu'jam al-Saghir. Its chain contains a narrator, Imran bin Khalid al-Khuza'i, and he is da'if (weak).