<Grid x:Class="MyNamespace.MyClass"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:local="clr-namespace:MyNamespace">
    <Grid.CommandBindings>
        <CommandBinding Command="local:MyClass.MyCommand" Executed="OnMyCommand" />
    </Grid.CommandBindings>
    <Button Command="local:MyClass.MyCommand" Content="Raise Command"/>
</Grid>