What is the basis for giving meat of qurbani as a gift to relatives and friends?

I've often heard that we should divide the meat of qurbani into three parts. 1. one should be eaten yourself and family 2. one should be given to the poor 3. and one should be gifted to relatives and friends I was listening to an online bayan and the imam said that we should eat from the meat of sacrifice because of the ayat of sura alhajj > 28-That they may witness benefits for themselves and mention the name > of Allah on known days over what He has provided for them of > [sacrificial] animals. So eat of them and feed the miserable and poor. > > 36-And the camels and cattle We have appointed for you as among the > symbols of Allah ; for you therein is good. So mention the name of > Allah upon them when lined up [for sacrifice]; and when they are > [lifeless] on their sides, then eat from them and feed the needy and > the beggar. Thus have We subjected them to you that you may be > grateful. This forms the basis of the first two fractions, but where is it written to give meat to friends and relatives?