Did the walls of Jericho say "oops" or "whee!!" on the way down? I mean when a grandson is the pastor's son he asks deep theological questions.
Let’s explore the relevant text, passed down through decades of oral tradition, from one generation to the next, each word carefully preserved, and I quote:
“Joshua fought the battle of Jericho, Jericho, Jericho.
Joshua fought the battle of Jericho,
And the walls came tumbling down.
SMASH!
You may talk about your men of Gideon,
You may talk about your men of Saul,
But there's none like good old Joshua,
At the battle of Jericho.”
From this, I can only conclude that the walls said “Smash” on the way down, and your grandson has strayed from the official church-sanctioned position.
I like it. I'll see if I can sell him on this answer.