Possible Clues:

• One has a duty so to thank the Bedouin
• Rate a menu
• Thanks to the Bedouin for something so taxing
• List of duties
• Kind of tax
• It's one's duty, thanks to the Bedouin
• Levy at the dock
• Charge, thanks to the Bedouin
• Charge resulting from quarrel about a ring-leader
• 'A charge, thanks to the Bedouin (6)'