1 Kings 10:15

Besides that he had of the merchantmen, and of the traffic
of the spice merchants
What they paid him as a duty or custom for the importation of their goods:

and of all the kings of Arabia;
who were subject to him, and paid him a yearly tribute, or at least made presents, see ( 1 Kings 4:21 1 Kings 4:24 )

and of the governors of the country;
who were viceroys or deputy governors of countries conquered by his father, and who collected tribute from the people, and paid it to him.