So this was the important matter he had been working on.

Thank you for your time and attention to this important matter.

And there was also the important matter of job security.

I have much on my mind and this is not an important matter.

But I never thought it was a very important matter in those days.

Thank you for your continued attention to this important matter.

"Could you tell me the nature of this important matter?"

Finally, I should like to raise another very important matter.

I think this is a really important and significant matter.

What he had in his head was the important matter.