Musnad Abu Ya'la al-Mawsili 159:95

And with his chain of narration, he said: The Messenger of Allah (ﷺ) said: "Were it not that I would make it difficult for my nation, I would have commanded them to use the siwak (tooth stick)." [Repeated]. And he said: "The Right Hand of Allah is full; spending does not diminish it, [neither] the pouring of the night nor the pouring of the day. Do you see what He has spent since He created the heavens and the earth? For it has not diminished what is in His Right Hand. And His Throne is upon the water, and in His other hand is the Balance; He lowers and He raises."