Arabic scale
There are many Arabic scales but one in particular is used by western composers to imply a middle eastern flavour. This scale can be thought of as a relative mode
of the harmonic minor, ie it is the same but starting on the fifth degree of the scale. It is very useful over a dominant 7th chord as it adds two colourful chromatic notes - the b13th and b9th (ex 11m, 11n)

ex 11m: Arabic scale
- harmonic minor starting on 5th degree of scale.

ex 11n : Arabic scale
used over a II-V-I sequence (or simply V-I)
Another way to think of this is to use the harmonic minor scale with the same root as the tonic chord that the V7 is leading to, so G7 uses a C harmonic minor but be careful not to emphasise the note C
inapropriately.
Used over a major V7 -I cadence the scale implies the modal interchange of the minor tonic for the major tonic, even though the minor tonic never materialises.The resolution to the major 3rd of the tonic is very satisfying after the bluesy
minor feel of the scale. This scale is obviously also very useful over a minor II-V-I.