Where did the expression

[Phuckeruppa]

"Griding their lions" come from?

[paraffin]

Don't you mean "girding their loins" ?

[novalis]

According to Brewer's Dictionary of Phrase & Fable:-

The Jews wore loose garments, which they girded ( belted ) about their loins ( waist ) when travelling or working.

[two-penneth]

Actually it IS 'Griding their lions' and it refers to an ancient game similar to 'Battleships' played by the Masai while tending their cattle in Kenya.

Each player has ten lions that he places randomly in a ten by ten grid (scratched in the sand, charcoaled onto a cow's behind etc) and they take turns trying to capture each other's lions.

The winner is the one who doesn't get eaten while they're distracted palying the game!

Next.