Question

Assalamu Alaikum.
Can you  give me some Hadeeth which gives the importance of reciting the Qur'aan according to Tarteel?

Answer

Wa alaikum assalaam wa rahmatu Allahi wa barakatuh.  The first in rank of importance is the order of Allah, ta'aalaa, in the Qur'an to recite the Qur'an with tarteel, in Al-Muzzammil aayah 4:

  , the explanation of the meaning can be translated as: ((And recite the Qur'an with measured recitation)).  

There are not specific hadeeths though on the importance of "tarteel" because the Arabs spoke with what is now known as tajweed.  The rules of tajweed were laid down scholars by  later after many non-Arabs entered Islam and the Arabic language weakened. In the beginning era after the Qur'an was revealed, there was no such need for this.  The only part of tajweed that was may not have been part of their normal speech at that time were the lengthenings, as it was mentioned specifically in more than one hadeeth, one such being:

 Qataadah narrated that he said, "I asked Anas bin Maalik about the recitation of the Prophet, , and he said, 'He used to lengthen [certain sounds] very much.'" Al-Bukhari

 We know that the Messenger of Allah, ,  recited in a beautiful voice: Abdullah bin Mughaffal said,  " I saw the Prophet, reciting the Qur'an while he was riding on his she-camel or camel which was moving, carrying him.  He was reciting surah Al-FatH, or part of surah Al-FatH smoothly and in an attractive vibrating tone."  Al-Bukhari

Another hadeeth pointing out the beauty of the Prophet's reciation is: Baraa' bin 'Aazib, may Allah be pleased with him, said, "I heard the Prophet, , recite in Isha' prayers "wa-t-teen wa-z-zaytoon", and I have not heard anyone with a better voice than him."  Bukhari and Muslim. 

The Messenger of Allah, , pointed out that some of the companions were better in tarteel than others when he said,  "Who wants to recite the Qur'an fresh as it was revealed, then he should recite the way of the recitation of bin Umm 'Abd [meaning Abdullah bin Mas'ood]." Ibn Maajah. Graded as hasan by Sheikh Albani

The Messenger of Allah, , said "One who does not read the Qur'an melodiously is not from us"  Related by Abu Dawood and graded as saheeh by Sheikh Albani.