There's a word there. It's an important word. And probably one we'd rather weren't written on the page.
The writer is referring to the relentless physical ageing of the body but I believe the metaphor is much bigger than that. For me, the rain clouds refer to the spiritual darkness hanging over us. I have joked that I didn't grow up until I turned 40 but I'm only half-laughing when I say it. Because actually, that's when I started to see firsthand the potential for evil which lies in the heart of humankind and that's when my eyes started to open and that is certainly when the rain clouds started to darken my sky. And I hate to have to tell you this, whatever the rain clouds represent, they are guaranteed to darken your sky too.
Our response to the inexplicable and relentless evil we see in this world can only be this: remember Jesus. Remember Jesus who was shamed and betrayed and lied to. Remember Jesus who was whipped and tried and hung on a cross to die.
Because He gets it too.