He had never expected that such an occasion would arise again- but here it was.

Why, I would have you help me as the occasion may arise.

Tell us what we can do for you when the occasion arises.

Such occasions arise with the use of it and there.

That is something we are convinced will happen, if the occasion should arise.

And I have no doubt that some day in the future they will be back again if the occasion arises.

When this occasion arose, I was the one allowed to go.

Of course, I filed her comment away for future use if the occasion should arise.

We talked very little, they no more than giving me a word of guidance when the occasion arose.

That would also be something for me to share with her when the occasion arises.