[BILBONDER]

There is a weaker vesrsion saying "Book of Allah and my Sunnah" but what is correct is the one I posted above, if you need narrations about the importance of Sunnah I can post a few for you:

Anas ibn Malik (ra) narrated that the Prophet SAWS said:
فمن رغب عن سنتي فليس مني "He who abandons my Sunnah then he is not from me."

He also narrated that SAWS said:
ذلك من سنتي ومن أحب سنتي فقد أحبني ومن أحبني كان معي في الجنة "That is from my Sunnah, he who loves my Sunnah then he loves me, he who loves me will be with me in Jannah."

Bilal bin al-Harith al-Mazni (ra) narrated:
من أحيا سنة من سنتي قد أميتت بعدي ، فإن له من الأجر مثل من عمل بها من الناس لا ينقص ذلك من أجورهم "He who revives one of my Sunnahs after it was abandoned after my death, he will get like the reward of all those who follow it and it will not decrease them."

'Amro ibn 'Awf (ra) narrated that he SAWS said:
فطوبى للغرباء الذين يصلحون ما أفسد الناس من بعدي من سنتي "Glad tidings be to the strangers who restore what the people corrupted from my Sunnah after I die."

al-'Irbad (ra) narrated from him SAWS:
من يعش منكم فسيرى اختلافا كثيرا، فعليكم بما عرفتم من سنتي، وسنة الخلفاء الراشدين المهديين "He of you who shall live after me will see great difference, so follow what you know from my Sunnah and that of the rightly guided Caliphs."