This verse alludes to the sinner's heart that might become as hard as a stone or even harder than that! Through this verse, QURÄN places a poetical allegory before us, that there are stones from which streams gush out, but the hardened heart of sinner, like that of the rebellious and obstinate Jews, will not melt to tears, and open to repentance. There are also some other stones which when split; water may issue out, and yet the hard hearted sinner is worse than all these, because nothing can soften them or change the state of their hardness, to shed some tears of repentance! (Wise men often change their mindes, but unwise never do that!. T. N.