In The Name of Allaah, The Most Merciful, The Bestower of Mercy
Imaam Ash’Shaatibee [rahimahullaah] said:
Know that Allaah has established this sharee’ah as a proof against the creation [i.e. mankind and jinn] – the old and young alike; the obedient and the disobedient; the righteous and the wicked. Allaah did not specify the proofs against anyone in exclusion of others. Likewise, all the other revealed laws were established as proof against the other nations to whom those laws were revealed.
The Sharee’ah is the judge- restrictedly and unrestrictedly. It is the judge for all those who have reached the age of responsibility. It is the path connected to [what Allaah has ordained] and the Greatest Guide. And have you not seen the statement of Allaah [The Most High]:
وَكَذَٲلِكَ أَوۡحَيۡنَآ إِلَيۡكَ رُوحً۬ا مِّنۡ أَمۡرِنَاۚ مَا كُنتَ تَدۡرِى مَا ٱلۡكِتَـٰبُ وَلَا ٱلۡإِيمَـٰنُ وَلَـٰكِن جَعَلۡنَـٰهُ نُورً۬ا نَّہۡدِى بِهِۦ مَن نَّشَآءُ مِنۡ عِبَادِنَاۚ وَإِنَّكَ لَتَہۡدِىٓ إِلَىٰ صِرَٲطٍ۬ مُّسۡتَقِيمٍ۬
And thus We have sent to you (O Muhammad) Ruhan (an Inspiration, and a Mercy) of Our Command. You knew not what is the Book, nor what is Faith? But We have made it (this Qur’an) a light wherewith We guide whosoever of Our slaves We will. And verily, you (O Muhammad) are indeed guiding (mankind) to the Straight Path (i.e. Allah’s religion of Islamic Monotheism).’’ [Soorah Ash-Shooraa. Ayah: 52]
He [alayhis salaatu wassalaam] was the first to be guided to the Book and Eemaan, and then those who followed him. The Book is the Guide and also the Sunnah which was revealed to him explains that guidance [i.e. the Sunnah and the Qur’aan explain each other]. All the creation [i.e. mankind and Jinn] are guided by it.
So when this is the case, the Sharee’ah is worthy of being a decisive proof against them and a guide by way of which they are guided to the truth. Their nobility is established in accordance with how much they embrace its rulings- through acting upon them in speech, belief and deeds– and not merely due to the level of their intellects or their nobility amongst their people. That is because Allaah [The Most High] determined nobility through Taqwa and not other than it. Allaah [The Most High] said:
[إِنَّ أَڪۡرَمَكُمۡ عِندَ ٱللَّهِ أَتۡقَٮٰكُمۡۚ- Verily, the most honourable of you with Allah is that (believer) who has At-Taqwa] [49:13]
The one who is the firmest in adherence to the Sharee’ah is more worthy of honour and nobility; therefore, honour is [measured] in accordance with one’s [level of adherence] to the Sharee’ah.
[Source: Al-Itisaam 3/434. Abridged and slightly paraphrased]