Surah Al-Jathiyah (chapter 45) ayat 18 beech wooden wall calligraphy

Beautiful Islamic calligraphy on decorative beech wooden wall panel displaying verses 45:18 from the Holy Quran.

Ayat 18 from surah 45, Al-Jathiyah, refers to the moment that the Prophet Muhammad (saws) was ordained to follow the revelations that he had received and got appointed with the responsibility in which children of Israel had failed, is the mission of guiding the humanity towards Allah (swt) according to the revelation that He sent. 

This is also the moment where the revelation became the "sharia" being a clear difference between the right path and everything else with strict orders from above to follow it and do what is right independent of what the rest is doing. 

﷽

ثُمَّ جَعَلْنَاكَ عَلَىٰ شَرِيعَةٍ مِّنَ الْأَمْرِ فَاتَّبِعْهَا وَلَا تَتَّبِعْ أَهْوَاءَ الَّذِينَ لَا يَعْلَمُونَ - 45:18

Then We put you, [O Muhammad], on an ordained way concerning the matter [of religion]; so follow it and do not follow the inclinations of those who do not know. 45:18

Surah Al-Jathiyah, verse 18 is the only verse in the Holy Quran that explicitly mentions the term "sharia". Linguistically, the Arabic term sharia means "a straight, smooth path that leads to water" which in the context of Arabian desert culture could also mean "a path to salvation from death". Some scholars are of the opinion that the term "sharia" was initially understood as referring to morality, not a set of laws. This term later became a technical term for Islamic law;

This surah starts with the special letters of ‘Ha Meem’ that Allah (swt) revealed in the various parts of the Holy Quran and its meanings only He knows; Seven successive chapters begin with the initial letter combination  “Ha-Meem” of which surah Al-Jathiyah (45) is the sixth. Other chapters starting with this mystical sets of letters are surah Ghafir (40), surah Fussilat (41) surah Ash-Shuraa (42), surah Az-Zukhruf (43),  surah Ad-Dukhan (44) and surah Al-Ahqaf (46).

_{NB: No translation of the Holy Quran can reflect the full debts of its original revelation in Arab and always has to be considered as one of sometimes multiple meanings or ways of translating that is possible when translated in any language.}