that the Messenger of Allah (ﷺ) said: "By the One in Whose Hand is my soul! You will not enter Paradise until you believe, and you will not believe until you love one another. Shall I inform you about a matter which if you do it, then you will love one another? Spread the Salam among each other."
Jami` at-Tirmidhi Book 42, Hadith 1
← Previous Hadith that the Messenger of Allah (ﷺ) said: "The wise statement is the lost property of the believer, so wherever he finds it, then he is more worthy of it."

Jami` at-Tirmidhi Book 41, Hadith 43 Next Hadith → "A man came to the Prophet (ﷺ) and said: 'As-Salamu 'Alaykum (Peace be upon you).'" "So the Prophet (ﷺ) said: 'Ten.' Then another came and he said: 'As-Salamu 'Alaykum Wa Rahmatullah (Peace be upon you, and the mercy of Allah).' So the Prophet (ﷺ) said: 'Twenty.' Then another came and said: 'As-Salamu 'Alaykum Wa Rahmatullahi Wa Barakatuh (Peace be upon you, and the mercy of Allah, and His Blessings).' So the Prophet (ﷺ) said: 'Thirty.'"

Jami` at-Tirmidhi Book 42, Hadith 2