To Him [alone] is the supplication of truth. And those they call upon besides Him do not respond to them with a thing, except as one who stretches his hands toward water [from afar, calling it] to reach his mouth, but it will not reach it [thus].1 And the supplication of the disbelievers is not but in error [i.e., futility].
Translation: Saheeh International (English)
1 The analogy indicates that false deities will never respond to them at all.
The call of monotheism is for Allah alone and no one shares this with Him. The idols on whom the idolaters call besides Him do not respond to the call of those who call them in any matter. Their calling them is simply like a thirsty person stretching his hand towards water for it to reach his mouth so that he can drink from it. The water is not going to reach his mouth. The call of the disbelievers to their idols is only in vain and far from being right, because they have no power to draw any benefit for them nor ward off any harm from them.