Hi,
The articles in any tax treaty are reciprocal. You may find it easier to substitute 'contracting state' with Saudi Arabia and 'other contracting state' with UK, or vice versa and re-read the article. In prinicple, if you are a resident of the UK, then you are taxable on your worldwide income in the UK and the article is stating those situations where it would not be taxable in the UK. For a more detailed explanation, you will need to contact our Self Assesment team for advice, or seek professional advice.
Self Assessment: general enquiries
Thank you.