فَعَسَى رَبِّي أَن يُوْتِيَنِ خَيْرًا مِّن جَنَّتِكَIt may be that my Lord will give me something better than your garden, (in the Hereafter), وَيُرْسِلَ عَلَيْهَاand will send on it,on your garden in this world, which you think will never come to an end or cease to be,حُسْبَانًا مِّنَ السَّمَاءHusban from the sky,Ibn Abbas, Ad-Dahhak and Qatadah said -- and Malik narrated that Az-Zuhri said -- a punishment from heaven.The apparent meaning is that it is a mighty rain which would disrupt his garden and uproot its plants and trees.As he said:فَتُصْبِحَ صَعِيدًا زَلَقًاthen it will be as a barren slippery earth.meaning, smooth mud in which one cannot get a foothold.Ibn Abbas said,"Like land without vegetation, where nothing grows.