Tafsir of Al-Mu'minoon 23:73

God has established the proof against them in these verses and severed their excuses and pretexts. He did so by showing that the one sent to them is a man whose affairs and state are well-known, whose inner and outer life has been tested, and who is worthy of being chosen for the message from among them. He did not present himself to them to make such a great claim falsely, nor did he make it a ladder to attain their worldly goods or beg for their wealth. He invited them to nothing but the religion of Islam, which is the Straight Path.

He exposed their hidden ailments: their failure to reflect and contemplate, their reckless adherence to the religion of their misguided forefathers without proof, their excuse that he is "possessed" despite the manifestation of the truth and the confirmation of his veracity from God through miracles and clear signs, and their hatred of the truth and turning away from the Reminder that contains their benefit.

It is possible that these people are described as those who do not believe in the Hereafter. {...are deviating} means they are turning away from this aforementioned path—that is, the "Straight Path." Indeed, everyone who does not believe in the Hereafter deviates from the right course.

When Thumamah ibn Uthal al-Hanafi embraced Islam and returned to Yamama, he cut off the supply of provisions to the people of Mecca. God afflicted them with years of drought until they were forced to eat al-‘ilhiz (a mixture of fur and blood). Abu Sufyan came to the Messenger of God (ﷺ) and said: "I adjure you by God and the ties of kinship: do you not claim that you were sent as a mercy to the worlds?" He replied, "Yes." Abu Sufyan said, "You have killed the fathers with the sword and the sons with hunger."

{And even if We had mercy on them and removed the distress they were in, they would persist in their transgression, wandering blindly. And We had already seized them with punishment, but they did not yield to their Lord, nor did they humble themselves. Until, when We open for them a gate of severe punishment, they will be in despair therein.}