What does « Some / A part » mean in the Quran?

And there came a company of travelers; then they sent their water drawer, and he let down his bucket. He said, "Good news! Here is a boy." And they concealed him, [taking him] as merchandise; and Allah was knowing of what they did.

And he said to the one whom he knew would go free, "Mention me before your master." But Satan made him forget the mention [to] his master, and Joseph remained in prison several years.

And [Joseph] said to his servants, "Put their merchandise into their saddlebags so they might recognize it when they have gone back to their people that perhaps they will [again] return."

And when they opened their baggage, they found their merchandise returned to them. They said, "O our father, what [more] could we desire? This is our merchandise returned to us. And we will obtain supplies for our family and protect our brother and obtain an increase of a camel's load; that is an easy measurement."

So when they entered upon Joseph, they said, "O 'Azeez, adversity has touched us and our family, and we have come with goods poor in quality, but give us full measure and be charitable to us. Indeed, Allah rewards the charitable."