What does « To mix / To blend » mean in the Quran?

To this world and the Hereafter. And they ask you about orphans. Say, "Improvement for them is best. And if you mix your affairs with theirs - they are your brothers. And Allah knows the corrupter from the amender. And if Allah had willed, He could have put you in difficulty. Indeed, Allah is Exalted in Might and Wise.

And to those who are Jews We prohibited every animal of uncloven hoof; and of the cattle and the sheep We prohibited to them their fat, except what adheres to their backs or the entrails or what is joined with bone. [By] that We repaid them for their injustice. And indeed, We are truthful.

And [there are] others who have acknowledged their sins. They had mixed a righteous deed with another that was bad. Perhaps Allah will turn to them in forgiveness. Indeed, Allah is Forgiving and Merciful.

The example of [this] worldly life is but like rain which We have sent down from the sky that the plants of the earth absorb - [those] from which men and livestock eat - until, when the earth has taken on its adornment and is beautified and its people suppose that they have capability over it, there comes to it Our command by night or by day, and We make it as a harvest, as if it had not flourished yesterday. Thus do We explain in detail the signs for a people who give thought.

And present to them the example of the life of this world, [its being] like rain which We send down from the sky, and the vegetation of the earth mingles with it and [then] it becomes dry remnants, scattered by the winds. And Allah is ever, over all things, Perfect in Ability.