Possible Clues:

• Assign (to job)
• Fill post -- a quiet position in field
• Put one in the post - full stop, by the sound of it
• Assign job to (someone)
• Pick a president in time
• Ordain a priest, coming to critical moment
• One could furnish a needle with one, by the sound of it
• Establish a quantity of liquid has been taken out of river
• Get the post sorted
• Get Father to be the one to turn up at this juncture