I was recently emailing with a friend of mine.
I offered this individual a gift.
They responded, "you don't have to, it's not necessary."

No true gift is free of risk.

My quick analysis is that giving a gift was a disruption.

Here's how I imagine their subconscious to have responded:

"I have everything that I need, am I missing something? Oh no! Maybe I don't! Quick, do I have everything? What do I need? Do we have food?" - Friend’s Subconscious

Then they calmly respond, "You don't have to, it's not necessary."

For 1/10 of 1/100000ths of a second, there was a momentary risk. A feeling that they might not have what they need - a disruption. Then, followed by acceptance.  

Of course, giving a gift is not necessary.

That's why we give gifts.