How to handle space in Sub Var value in Maxl in Linux

I am executing the below Maxl command in Linux and having trouble passing the value 'abc xyz' as one string input to the Maxl.

alter database $appname.$dbname set variable $variablename $Value

Value= 'abc xyz';

The $variablename gets set with abc. It ignores xyz. It is taking them as two different parameters for every space. The same command works in windows and the variable is set to 'abc xyz' which is the requirement.

I have tried passing the variable under ' ' which means I am asking it to consider as one string. It still doesn't work. Has anyone faced this issue? Any help is appreciated.