insert 2 lines matrix inside another matrix and conditionally repeating them

I want to integrate two lines inside matrix and repeated frequently depending on next lines like the following example:

The original matrix:

A = [ G1 X8 Y118
      G0 X8 Y135
      G1 X 8 Y 150
      G0 X 8 Y 172
      G1 X 8 Y 209
      G0 X 8 Y 242
      G1 X 8 Y 410
      G0 X 9 Y 208

…….. ] so on

Generated matrix

AA = [ 
M 802
M 800 P 8
G1 X8 Y118
M802   
M800 P9    
G0 X8 Y135    
M 802   
M 800 P 8   
G1 X 8 Y 150   
M 802  
M 800 P 9    
G0 X 8 Y 172    
M 802   
M 800 P 8    
G1 X 8 Y 209    
M 802    
M 800 P 9    
G0 X 8 Y 242    
M 802   
M 800 P 8    
G1 X 8 Y 410      
M 802  
M 800 P 9  
G0 X 9 Y 208 

…………] so on

So before any line begin with G1, put

M802

M800 P8

And before any line begin with G0, put

M802

M800 P9

How can we do this?