Abu Dawud

Benefits and Issues:
➊ Saying "As-salamu alaykum," that is, making it a habit to greet with salam at appropriate times, is an important part and symbol of Islamic social conduct.
➋ If making salam a regular practice, distances are eliminated and closeness increases, and additional reward and merit are attained. In fact, it is proof of the completion of faith (iman) and entitlement to enter Paradise.

Explanation:
1:
From this hadith, it is understood that the fundamental requirement for entering Paradise is faith (iman),
and for the perfection of faith, mutual love and brotherhood are necessary,
and if one wishes to preserve these, then spread the greeting of peace (salam) widely and make it common.

Commentary:
(1)
Faith (iman) is an essential condition for entry into Paradise.

(2)
Those with complete faith will enter Paradise without undergoing any punishment in Hell, whereas those with deficient faith will be taken out of Hell after receiving punishment for their sins.

(3)
Love that is based on faith, rather than on color, lineage, family, language, homeland, or emotions, is a cause for the perfection and beauty of faith.

(4)
Greeting one another with salam is a means of mutual love, because the words "as-salamu alaykum" and "wa alaykum as-salam" are both an expression of good feelings for each other and a supplication for well-being.

(5)
The Prophet of Allah (sallallahu alayhi wa sallam) has mentioned many things to create mutual love among Muslims, such as: giving gifts, calling each other by good names, shaking hands when greeting with salam, embracing after meeting again after a long time, keeping the rows straight in congregational prayer (salah) and standing with feet to feet and shoulder to shoulder, helping each other in times of need, participating in each other's happiness and sorrow, respecting elders, and showing kindness to the young, etc.

Commentary:
(1)
Faith (iman) is an essential condition for entering Paradise.

(2)
Mutual love is a means for the completion of faith (iman), therefore, all those actions should be performed which generate mutual love, and those actions should be avoided from which there is a fear of mutual hatred arising.

(3)
Greeting one another with salam is an excellent means of establishing and maintaining good relations among each other.
In other ahadith, some other matters have also been mentioned, for example:
Shaking hands (musafahah), embracing (mu‘anaqah), and giving gifts. See: (Muwatta Imam Malik: 2/408, Hadith: 1731, and Al-Adab Al-Mufrad, Hadith: 594)

Benefits and Issues
➊ From the mentioned hadith, it is understood that faith (iman) is a condition for entering Paradise; if there is no faith, Paradise will not be attained.
➋ It is also understood that mutual love is a means for the completion of faith; therefore, one should do those deeds which become a means for the completion of faith and which create mutual love. And one should avoid those deeds which cause mutual hatred, envy, and malice.
It is narrated from Sayyiduna Abu Hurairah (radi Allahu anhu) that the Noble Prophet (sallallahu alayhi wa sallam) said:
“Exchange gifts with one another, for this will create mutual love.” [ادب المفرد للبخاري، رقم : 594]
➌ In the aforementioned hadith, the importance of saying “as-salamu alaykum” to one another is also established, as it creates mutual love. If there is mutual love, then one will become a true Muslim.