Time.

That's it. Offer your time if you care giving the best gift.

Time is the most valuable thing a man can spend. – Theophrastus

Sounds like right.

Time is an illusion. – Albert Einstein

Yet, it's very personal. That's why beware that most of the people won't really understand what you put on the table.

Time is free, but it’s priceless. You can’t own it, but you can use it. You can’t keep it, but you can spend it. Once you’ve lost it you can never get it back. – Harvey Mackay

Better invest it.

Musk always repeats that his top goal is to bring efficiency such that same things take less time, not to accumulate more money.

Time is money. – Benjamin Franklin

On the other hand, it also (a lot of) money.

The key is in not spending time, but in investing it. – Stephen R. Covey

Like your money. More can easily earn/save more.

Lost time is never found again. – Benjamin Franklin

Health might compete but it's also time, isn't it?

It is the time you have wasted for your rose that makes your rose so important. – Antoine de Saint-Exupéry, The Little Prince

There’s only one thing more precious than our time and that’s who we spend it on. – Leo Christopher

Poetic.

Time is what we want most, but what we use worst. – William Penn

So, watch out, probably you will give your time to someone who isn't worth of it.