Allāh has knowledge of everything.
Dāwūd عليه السلام was blessed with the skill of being able to mould iron. It would miraculously soften for him.
Very few people are truly grateful to Allāh.
The people of Saba were blessed greatly by Allāh, but this changed dramatically when they were ungrateful.
Allāh is the only one who sustains us.
The Prophet ﷺ sought no recompense from the people for fulfilling his duty of prophethood.