As for “righteous kings,” consider His words, glorified is He:

“Allah has appointed Saul as your king.” They said, “How can he have kingship over us when we have a greater right to it than he does, and he has not been given abundant wealth?” He said, “Allah has chosen him over you and endowed him abundantly with knowledge and stature. Allah grants His kingship to whom He wills. Allah is All-Bountiful, All-Knowing.”

“Their prophet said to them, ‘The sign of his kingship is that the Ark will come to you.’”

And His words, glorified is He:

“They ask you about Dhū al-Qarnayn. Say, ‘I will relate to you an account of him.’”

“We established him firmly in the land and gave him the means to accomplish everything”—and so forth.

Mujāhid said: “Two believers and two disbelievers ruled the earth. The two believers were Solomon and Dhū al-Qarnayn, and the two disbelievers were Nebuchadnezzar and Nimrod. A fifth, from this community, will rule it.”

And His words, exalted is He:

“O my people, remember Allah’s favor upon you when He raised prophets among you and made you kings.”

As for “kings in general,” references to them are numerous, such as His words:

“Beyond them was a king who seized every ship by force.”

And His words:

“The king said, ‘I see seven fat cows being eaten by seven lean ones.’”