William Kilpatrick posted the remark on the site using his mobile phone as he left the branch of Morrisons where he worked, his trial at Stirling Sheriff Court was told.
It read: “Neil Lennon...get mair bullets and bombs sent, boys, Glasgow Rangers Champions.”
Kilpatrick, who was detained after a colleague told police about the remark, told officers it was “banter”.
Kilpatrick, 22, of Bannockburn, denies posting an offensive and threatening messafe on the site, thereby inciting others to commit violence and causing a breach of the peace.
He further denies behaving in a threatening and abusive manner by way of the Facebook post.
The incident is said to have occurred on April 24th, 2011, which jurors were told was the day of an Old Firm Game.
The trial is due to continue on Friday.