(… ذَٰلِكَ هُدَى اللَّهِ) (That is the guidance of Allah …): All that has been mentioned is the guidance of Allah (swt). We have explained that guidance is of two types, Directional Guidance and Supportive Guidance. All the Prophets were tasked with the former, i.e., Directional Guidance. Therefore, the guidance of Allah comprises of the Divine Messages and the conveyance that the Prophets have been tasked to carry out.

(… يَهْدِي بِهِ مَن يَشَاءُ مِنْ عِبَادِهِ… ) (…by which He guides whomever He wills of His servants.…): Someone might come claiming: ‘Allah did not will to guide me.’ In answer, we say: ‘He did not will guidance for you when you did not choose it. He has left the choice up to you and has given you free-will. If He had not willed it, you would not possess your own free-will, and He would force the choice upon you, as He says: 

 وَلَوْ شَاء رَبُّكَ لآمَنَ مَن فِي الأَرْضِ كُلُّهُمْ جَمِيعًا أَفَأَنتَ تُكْرِهُ النَّاسَ حَتَّى يَكُونُواْ مُؤْمِنِينَ

(Had your Lord so willed (O Prophet), all (people) on earth would have certainly believed, every single one of them! Would you then force people to become believers?) (Yunus: 99)

Therefore, a human being will be reckoned based on his choices and not based on Allah’s Knowledge of his choices. This is the focal point for being tasked with responsibilities, and the focal point for rewards or punishments. This matter is clear to all human beings. Allah (swt) has commanded us to follow this path, but we are the ones who have chosen other than it, so: (by which He guides whomever He wills of His servants.) It is of Allah’s will that He has made for human beings free-will. If He had willed otherwise, He would not have given it to them.

(  وَلَوْ أَشْرَكُوا لَحَبِطَ عَنْهُم مَّا كَانُوا يَعْمَلُونَ… ) (…But if they had associated others with Allah, then worthless for them would be whatever they were doing): Therefore, any deed which comes together with associating others with Allah in worship will not be of any use.