If you don't want to know the circumstances surrounding Thursday's entry in this slideshow, then don't read any further...
[spoiler]Thursday's quote:
Ep #315 (1967) - Julia - 'Barnabas, I MUST insist that you stay here for the time being.'
From '#0315/0316: Robservations 01/15/02: "Hullo, David!"'
She wants him to wait 15 minutes for an injection,
[/spoiler]
Because there aren't many details during this period, the Robservations doesn't reference the quote. However, as Barnabas goes to get his cape, Julia delivers the quote. Barnabas warns her that his patience is not without its limits and if she interferes with his plans, she'll come to regret it. But Julia explains he needs to have another injection and the timing of them is of vital importance...
And this is the third quote from this ep. The first (Sarah - 'They MUST be very worried about you') was back on April 25th, and the second (Barnabas - 'I MUST find David before anybody else does') was back on August 13th.