The evidence is the statement of Allāh, the Mighty and Exalted:

And if only they had acted according to the Torah, the Gospel and what has (now) been sent down to them from their Lord (the Qurʾān), they would surely have gotten provision from above them and from underneath their feet. There are from among them people who are on the right course but many of them do evil deeds. ^[1]

Abiding by and adhering to what Allāh has revealed of legislation is a means of provision from above (the heaven) and below (the Earth) and this applies to all without exception, both the rulers and the ruled, and in matters of belief, worship and methodology.

Footnotes