Monks and nuns say "Thank you" by their silence.
They say "Thank you" through their practice.

By their practice,
monks and nuns give the opportunity to others to do good deeds
by supporting their practice and all that comes around it.
The opportunity to give in this context, itself, is rare.

As the Buddha said:
"The gift of Dhamma is the highest gift."

Monks and nuns have no material possessions,
and for the lay community,
generosity is the special bridge by which
a person gets the chance to see
and interact with the monastic community.

This contact itself is the gift.

The Buddha teaches us to give without expectations.
That is the proper way to give.
To give with a free and uplifted mind,
understanding how fortunate one is
only to give,
to support the good Dhamma
wishing for their gift to benefit all sentient beings.

This will be for the giver's welfare and happiness.
Here and now and in times to come.