What is the evidence regarding the fact that doing something makruh is not sinful but one who stays away from it for the sake of Allah is rewarded?

We know many things are makruh/disliked in Islam. Like standing while drinking water. But what is the evidence regarding the fact that doing something makruh is not sinful but one who stays away from it for the sake of Allah is rewarded? Could you provide the evidence for it from the quran or sunnah?