Green’s Dictionary of Slang

1. (also Isle) the right side.

1960		J. Franklyn Dict. of Rhy. Sl.
1972		Dodson & Saczek Dict. of Cockney Rhy. Sl.
2001		M. Coles Bible in Cockney 99: I really don’t have the right to choose who’s gonna sit at me Isle and me left.

2. right, permission.

1960		J. Franklyn Dict. of Rhy. Sl.
1971		J. Jones Rhy. Cockney Sl.
2001		M. Coles Bible in Cockney 102: What Isle-of-Wight do you have to go around doing all this stuff?