In The Name of Allaah, The Most Merciful, The Bestower of Mercy.

The Prophet [sallal laahu alayhi wasallam] said, “I was sent to perfect noble manners”.

Al-Allaamah Zayd Bin Haadee Al-Madkhalee [rahimahullaah] said: “This hadeeth is from the Jawaami Al kalim of the Messenger [i.e. a precise statement whose meaning is vast]. In it is proof regarding the importance of good manners and how can that not be the case when it is the fact that the Prophet [sallal laahu alayhi wasallam] said (in another hadeeth), “Righteousness is good character”. Therefore, it is obligated on a believer to have good manners in his relationship with his Lord and in his dealings with the people. His manners should be based on the judgement of the noble Islamic legislation – in speech, deeds, dealings and all his actions. [Ref 1]

Al-Allaamah Rabee Bin Haadee al-Madkhalee [hafidhahullaah] said:

Knowledge is not merely about studying and obtaining certificates, rather the goal is to acquire sound and precise understanding – sound understanding in affairs of Aqeedah, worship, good manners, good etiquettes and everything related to the life of a believer.  It is obligated on the believers to carry out everything related to their lives based on the Book of Allaah and the (authentic) sunnah of Allaah’s Messenger [sallal laahu alayhi wasallam]. The believer performs acts of worship sincerely for the Sake of Allaah because Allaah commanded him to be sincere. [Allaah (The Blessed and Exalted) said]:

وَمَآ أُمِرُوٓاْ إِلَّا لِيَعۡبُدُواْ ٱللَّهَ مُخۡلِصِينَ لَهُ ٱلدِّينَ حُنَفَآءَ وَيُقِيمُواْ ٱلصَّلَوٰةَ وَيُؤۡتُواْ ٱلزَّكَوٰةَ‌ۚ وَذَٲلِكَ دِينُ ٱلۡقَيِّمَةِ

And they were commanded not, but that they should worship Allah, and worship none but Him Alone (abstaining from ascribing partners to Him), and perform As-Salat (Iqamat-as-Salat) and give Zakat: and that is the right religion. [Surah Al-Bayyinah’ Aayah 5] [Ref 2]

Good manners have far-reaching outcomes and this why Allaah and His Messenger commanded us to have good manners. The Messenger [sallal laahu alayhi wasallam] used to apply these good manners when dealing with people – when dealing with his family in his house, his companions and adversaries. Even when a Yahoodi greeted the Messenger of Allaah and said, “As-Saamu Alaykum – death be upon you”, he replied, “Alaykum- And upon you’’. Then Aa’isha said to (the Yahoodi), “Wa Alaykumus Saam Wal la’nah – Death be upon you and the curse of Allaah”, so, the Messenger said, “O Aa’isha! Indeed, Allaah is kind and gentle and He loves kindness and gentleness”. Look (at how) the Yahoodi was dealt with kindly and gently! If he sees this kindness and gentleness, it may pull him towards Islaam or at least these lofty manners will repel a lot of the evil of this Yahoodi, and thus this would make you upright as well as your call to the Religion of Allaah [Ref 3]

[Ref 1: At-taleeqaatul Maleehah Alaa Silsilah Al-Ahaadeeth As-Saheehah. Vol 1. Page 143. Slightly paraphrased]

[Ref 2: Marhaban Yaa Taalibal Ilm’ pages 72 – 73. Slightly paraphrased]

[Ref 3: An Excerpt from Marhaban Yaa Taalibal Ilm’ page 88. slightly paraphrased]