Truly, the religion with Allâh is Islam

Question :

On what occasions or for what reasons were these two verses revealed? And what do they mean?
"Truly, the religion with Allah is Islam"

"And obey not everyone who swears much and is considered worthless, a Hammaz, going about with Namim, hinderer of the good, transgressor, sinful, "Uttul and moreover Zanim, because he had wealth and children."

Answer:

The first verse:
"Truly, the religion (Din) with Allah is Islam."

Means that the only religion that is accepted by Allah is Islam. The word Din is used here, which sometimes means action, and sometimes means reward for action. For example, Din means action in Allah's saying:
"And with Islam as your religion (Din)."

As well as His saying:
"Truly, the religion with Allah is Islam (Din)."

It also means the reward for the actions, as in Allâh's saying:
"The Only Owner of the Day of recompense (Din)."

His saying:
"Nay, but you deny the Recompense (Din)."

"Woe, that day, to those who deny. Those who deny the Day of Recompense (Din),"

The action that is accepted by Allâh Almighty is Islam, which means to surrender to Allah Almighty, outwardly and inwardly, and this embraces both Islam in the specific sense the religion of Muhammad-and Islam in the general sense the religion of all the Prophets. The religion of every Prophet was the religion of Allah Almighty, the religion of Islam. And the Shari'ah of one Prophet would continue until another came, abrogating it, and this new Shari'ah would become Islam Allah's religion, which alone is accepted.

So Allâh's saying:
"Truly, the religion with Allah is Islam (Din)."

embraces both the basic and secondary principles of religion, it also embraces the specific details of action: in both the general and the specific, Allah Almighty accepts only that which agrees with Islam.
The Messenger of Allah ﷺ said,
"Whoever does a deed that is not in accordance with our matter, then it is rejected."

This verse clearly shows that Allah Almighty does not accept other religions, regardless of the many deeds that their adherents may perform, and regardless of whether they are Jews, Christians, or adherents of any other religion.

And whoever believes that a religion is equal to Islam, or says that Allâh Almighty is pleased with all religions, he is a disbeliever, and should be asked to repent. If he doesn't repent, he should be killed, because all previous religions are abrogated by the religion that Allah Almighty revealed to Muhammad ﷺ ,for Allah Almighty says:

"And whoever seeks a religion other then Islam, it will never be accepted of him, and in the Hereafter he will be one of the losers."

As for the second verse in the question:
"And obey not everyone who swears much and is considered worthless, a slanderer, going about with Namim."

You asked why it was revealed; I don't know of any specific reason. But in it, Allah Almighty forbids his Prophet, Muham- mad, from obeying people who are of this description:
"everyone who swears much."

Meaning he often takes an oath to support what he says, because he is worthless and doesn't even himself believe in his words unless he swears to it;
"a Hammaz, going about with Numim."

Hammaz is excessive Ghibah (backbiting) about people,

"going about with Namim."

Spreading Namimah about people. The difference between backbiting (Ghibah) and slandering (Namimah) is that the backbiter says something about another person who is absent which that person doesn't like, and the slanderer seeks to sow dissension and mutual hatred among people.

An example of the latter is when a person says to someone else, "So and so says such and such about you; he curses you and finds fault with you." Thus he instills enmity between two people. In an authentic Hadith, the Prophet ﷺ said :
"The Nammam (slanderer) does not enter Paradise"

And we ask Allah Almighty to protect us. Next, Allah Almighty says :
"Hinderer of the good, transgressor, sinful."

Not only is such a person void of good, but he tries to prevent good from others. He prevents good from others and he transgresses against them, and the combination of these two qualities represents the utmost in wrongdoing. He is called "sinful" because of his many transgressions against others.

Then, Allâh Almighty says :
"Uttul and moreover Zanim"

Zanim means a person who is known for his evil and 'Uttul is a person who is cruel and haughty. The word Zanama derived from Zanim also means a some distinguishing mark on the neck of an animal.

Finally , Allâh Almighty says:
"because he had wealth and children. When Our Verses are recited to him he says: Tales of the men of old!
Such a man becomes proud of the wealth and children he has, and as a result, he becomes tyrannical. When verses of the Qur'an are read to him, he says, "Tales of the men of old!" This is because his heart is not open to the beautiful meanings of the Qur'an, to the higher moral code that it teaches, to the beneficial and true stories of past nations. A person whose heart becomes so engrossed in sins may be blocked from the guidance of the Qur'an, from its light, as Allah Almighty said:
"Nay! Truly the Records (writing of the deeds) of the Fujjar (rebellious) is (preserved) in Sijjin. And what will make you know what Sijjin is? A Register inscribed. Woe, that day, to those who deny. Those who deny the Day of Recompense. And none can deny it except every transgressor beyond bounds. When our verses are recited to him he says: Tales of the ancients! Nay! But on their hearts is the Ran (covering of sins and evil deeds) which they used to earn.

He only describes the Qur'an as being "tales of the ancients" because the light and guidance of the Qur'an have not reached his heart: how can it reach his heart when his heart has a covering of sins and evil deeds. The more a person is guided by Allah's verses, the more will he be increased in even more guidance; Allâh Almighty says:
"While for those who accept guidance, He increases their guidance, and bestows on them their piety."

And:
"And Allah increases in guidance those who walk aright."