The Messenger of Allah ﷺ said: "By Him in Whose hand my soul is, you will not enter Paradise until you believe, and you will not [truly] believe until you love one another. Shall I not guide you to something which, if you do it, you will love one another? Spread the salam among yourselves." [Muslim 54].

‘Ammar ibn Yasir رضي الله عنه reported: "Whoever combines three qualities has combined [complete] faith: fairness to oneself, greeting the whole world with salam, and spending [in charity] even in times of need." [al-Bukhari, as ta‘liq; see Fath al-Bari 1/82].

‘Abdullah ibn Salam رضي الله عنه reported that when the Messenger of Allah ﷺ arrived [in Medina], he said: "O people, spread the salam, feed others, maintain ties of kinship, and pray [at night] while people are asleep — you will enter Paradise in peace." [at-Tirmidhi 2485; Ibn Majah 1334; Sahih Ibn Majah 1/232].

‘Abdullah ibn ‘Amr رضي الله عنه said that a man asked the Messenger of Allah ﷺ: "Which of Islam's practices is best?" He replied: "That you feed [others] and offer salam to those you know and those you do not know." [al-Bukhari 12; Muslim 39].

The Messenger of Allah ﷺ said: "A Muslim has six rights over another Muslim." It was asked: "What are they, O Messenger of Allah?" He said: "When you meet him, greet him with salam; when he invites you, respond; when he seeks your counsel, give him sincere counsel; when he sneezes and praises Allah, say 'yarhamuka-Llah' to him; when he falls ill, visit him; and when he dies, follow his funeral procession." [Muslim 2162].