26:4

This voluntary belief, acceptance of the truth and rejection of falsehood, is what Allah demands from man.

That is, it is not at all difficult for Allah to send down a sign which would make all the disbelievers yield and submit. If, however, He does not send one, it does not mean that such a thing is beyond His powers, but the reason is that the belief under compulsion is not acceptable to Him. Allah wants that people should use their common-sense and recognize the truth through the verses of the divine Book and the signs which are scattered all over the universe and are found even in their own selves. Then, when their hearts are satisfied that the message of the Prophets contains the truth, and the beliefs and the creeds which are opposed to it, are false, they should willingly give up falsehood and adopt the truth.

26:5

Allah is explaining that nothing affects these people, just like a sick person who turns away from everything. Similarly, there is a disease in their hearts, and no matter how Allah tries to explain things to them, they will reject everything.

This is human nature to forget, which is why Allah repeatedly explains and teaches the same thing in different ways. He describes the same event in various manners so that if one way is not understood, another way might be. It's like a new set of arguments has been given to their minds, something fresh, except that they have ignored it entirely. In other words, the Quran is saying that it's not like I'm repeating myself with the same thing over and over again. The conclusion is the same, but Allah has offered different kinds of arguments to teach this very simple lesson.

26:8

That is, the seeker after truth does not have to look far for a sign. If only he sees with open eyes the phenomena of vegetation around him, he will be able to judge for himself whether the reality about the system of the world (i.e. Tauhid) which was being presented by the Prophets is true or not.

26:9

That is, He has the power and ability to annihilate completely anyone whom He wills to punish, but it is His mercy that He does not hasten to punish the wrong-doer, but gives him respite for years and centuries to allow him time to think, understand and mend his ways, and is ever ready to forgive the sins of a lifetime if the sinner offers repentance but once.

26:13-14

When Allah chooses someone for a task, He does not look at how skillful they appear to be in worldly terms. Allah looks at a person's inner self and their intentions. This is why Allah chose Moses despite his speech impediment. Even though he had killed a man, Allah still chose him. Allah's criteria for selection are different; He does not look at outward appearances. Allah saw goodness and the right intentions within Moses.

When someone cleanses their intentions and thoughts, they radiate positive energy. Everyone possesses an energy that draws things to them in the world. If someone harbors negative thoughts and bad intentions, they will attract negativity. Similarly, despite Moses' outward flaws, his inner goodness and compassion for others led Allah to choose him as a messenger.

26:17

The mission of the Prophets Moses and Aaron (peace be upon them) was twofold: First, to invite Pharaoh to the worship and obedience of Allah which has been the foremost aim of the mission of every Prophet Secondly, to liberate the Israelites from the bondage of Pharaoh, which was specifically assigned to them. The Quran has mentioned sometimes only the first part of their mission (as in Surah An-Naziat) and sometimes only the second.

26:18-19

Firawn manipulating Musa and changes the subject to make him feel bad and guilty about his past

Here, Pharaoh did not respond to Moses' words but began to manipulate him emotionally and make him feel guilty by reminding him of his past. Pharaoh did all this to shatter Moses' confidence and humiliate him in front of the assembly. For us, there is a lesson in this: often, when someone tells us about religion, we remind them of their past, saying, "Yes, we know what you used to do. Don't try to act too pious." This behavior is extremely wrong, just as Pharaoh did with Moses by reminding him of his past. It is true that a person cannot escape their past, and people often don't let one forget it. However, with Allah, sincere repentance can turn all past sins into good deeds.

26:20

Here, we also learn another lesson about how Moses handled the situation. He did not retaliate or fight back. Instead, he accepted his past, acknowledging, "Yes, I did it when I was ignorant, but now I have knowledge and guidance.”