Stick to the sunnah is a phrase you hear a lot. But what exactly does it mean? In this context, the word sunnah is not just the recommendations in the deen as can be understood when you are studying fiqh of prayer. Here the sunnah means the way of the Prophet Muhammad in belief and actions. His name is Muhammad ibn Abdullah and he is Mustafaa, because he was chosen and selected from amongst all of the Prophets to be the final messenger to all of humanity.
In Arabic the word Mustafaa, chosen, comes from the word to mean pure, or undiluted. So to stick to his sunnah is because he is the best one who was selected and chosen to be and his way is the best chosen path for us all. Stick to the sunnah represents the complete way of the prophet in everything related to ‘ibadah, or worship. When you imagine yourself being stuck to something, it means you are always with it and never leave it off.
Whereas on the other hand going against his sunnah is considered innovation and even worse, could be a form of heresy and disbelief.
There is a plethora of evidence in the Quran and the hadith tradition for the duty of following the Prophet Muhammad in beleif and actions. Allah commands us:
فَـَٔامِنُوا۟ بِٱللَّهِ وَرَسُولِهِ ٱلنَّبِىِّ ٱلْأُمِّىِّ ٱلَّذِى يُؤْمِنُ بِٱللَّهِ وَكَلِمَـٰتِهِۦ وَٱتَّبِعُوهُ لَعَلَّكُمْ تَهْتَدُونَ
So believe in Allah and His Messenger, the unlettered Prophet, who believes in Allah and His revelations. And follow him, so you may be ˹rightly˺ guided. (7:158)
In another ayat Allah warns us against opposing his way:
فَلْيَحْذَرِ ٱلَّذِينَ يُخَالِفُونَ عَنْ أَمْرِهِۦٓ أَن تُصِيبَهُمْ فِتْنَةٌ أَوْ يُصِيبَهُمْ عَذَابٌ أَلِيمٌ
So let those who disobey his orders beware, for an affliction may befall them, or a painful torment may overtake them. (24:63)
In the hadith On the authority of Abu Hurayrah Abdur’Rahman ibn Sakhr (may Allah be pleased with him) who said: “I heard the Messenger of Allah (peace and blessings of Allah be upon him) saying”: “What I have forbidden you, stay away from. What I have ordered you to do, do as much of it as you can”. [Reported in Bukhari and Muslim] and Abu Hurayrah (may Allah be pleased with him) reported that the Prophet (may Allah’s peace and blessings be upon him) said: “By the One in Whose Hand Muhammad’s soul is! There is nobody of this Ummah, be they Jewish or Christian, who hears of me and then dies without believing in what I was sent with except that he will be among the people of Hellfire.” [Reported in Muslim]
The sunnah includes the way of the Prophet in belief, the way of the Prophet in speech and the way of the Prophet in deeds. In other words, everything that the Prophet Muhammad worshipped Allah with, then it is legislated for us to follow him, either as an obligation if the action is obligatory or as a recommendation if the action is recommended. So stick to the Sunnah in belief, speech and deed!