That is, like one who stretches out his hands to grasp the water: one who tries to grasp water will have nothing in his hand, nor will any of it reach his mouth. Likewise, one who calls upon idols—which can neither harm nor benefit—will gain nothing.
It was also said that it means: like a thirsty man who sees water from afar, gestures toward it with his hand, and calls to it with his tongue, but it never comes to him. This is the meaning of Mujahid’s statement.
A similar interpretation is reported from Ali and Ata: it is like a thirsty man sitting at the edge (2) of a well, stretching his hand toward it, yet unable to reach the bottom of the well where the water is; nor does the water rise up to him. Thus, stretching out his hand toward the water and calling to it does him no good, nor does it reach his mouth. Likewise, those who call upon idols derive no benefit from calling upon them, for they are incapable of anything.
Ibn Abbas said: It is like a thirsty man who spreads out his hands in the water; this does him no good unless he scoops up water with them. The water will not reach his mouth so long as he merely holds out his hands. This is a parable Allah has struck for the disappointment of the disbelievers (3).
“And the supplication of the disbelievers”—to their idols—“is only in error”: it fails them when they are in need of it, as He said: “And whatever they used to invent will vanish from them.” (al-An‘am 24 and elsewhere)
Al-Dahhak reported from Ibn Abbas: “The supplication of the disbelievers to their Lord is only in error,” because their voices are veiled from Allah, Most High.
“And to Allah prostrates whoever is in the heavens and the earth, willingly or unwillingly, as do their shadows, in the mornings and the afternoons.” (15)
His saying, Most High, “And to Allah prostrates whoever is in the heavens and the earth, willingly,” refers to the angels and the believers; “and unwillingly” refers to the hypocrites and the disbelievers who were compelled to prostrate by the sword.
“And their shadows” means that the shadows of those who prostrate willingly and unwillingly prostrate to Allah, Most High, willingly. Mujahid said: “The shadow of the believer prostrates willingly, while he himself is willing; and the shadow of the disbeliever prostrates willingly, while he himself is unwilling.”
“In the mornings and the afternoons” means that when a person prostrates in the morning or the evening, his shadow prostrates along with him. Al-āsāl (afternoons) is the plural of al-uṣul, and al-uṣul is the plural of al-aṣīl, which is the time from the afternoon prayer until sunset.