Reference for Keritot 15:29

אמאי אוקימתא להא דתניא אין מביא בזב בעל ג' ראיות ליתנייה גבי חמשה מביאין קרבן אחד על עבירות הרבה

The first issue of a zab took place at a time fit for offerings, but in the instance of 'one by night', wh the issue was at a time not fit for offerings, had not R'Johanan taught us that they combine with one another, I would have thought that they do not combine.

Jastrow

Jastrow