What does « The letter Ba » mean in the Quran?

And [recall] when you said, "O Moses, we can never endure one [kind of] food. So call upon your Lord to bring forth for us from the earth its green herbs and its cucumbers and its garlic and its lentils and its onions." [Moses] said, "Would you exchange what is better for what is less? Go into [any] settlement and indeed, you will have what you have asked." And they were covered with humiliation and poverty and returned with anger from Allah [upon them]. That was because they [repeatedly] disbelieved in the signs of Allah and killed the prophets without right. That was because they disobeyed and were [habitually] transgressing.

How wretched is that for which they sold themselves - that they would disbelieve in what Allah has revealed through [their] outrage that Allah would send down His favor upon whom He wills from among His servants. So they returned having [earned] wrath upon wrath. And for the disbelievers is a humiliating punishment.

They have been put under humiliation [by Allah] wherever they are overtaken, except for a covenant from Allah and a rope from the Muslims. And they have drawn upon themselves anger from Allah and have been put under destitution. That is because they disbelieved in the verses of Allah and killed the prophets without right. That is because they disobeyed and [habitually] transgressed.

So is one who pursues the pleasure of Allah like one who brings upon himself the anger of Allah and whose refuge is Hell? And wretched is the destination.

Indeed I want you to obtain [thereby] my sin and your sin so you will be among the companions of the Fire. And that is the recompense of wrongdoers."