The Benefit And Etiquette of Eating By Hand in the Sunnah
Abu Huraira reported Allah's Messenger (صلى الله عليه وسلم) as saying:
“ When any one of you eats food he should lick his fingers,
for he does not know in what part of the food sticking to his fingers the
blessing lies. [Muslim]
...
Ibn Al-Qayyim mentions in his Prophetic Medicine regarding
the number of fingers the Prophet would use to eat his food:
“ He used to eat with his three fingers, which is the best way
to eat. Eating with one finger or with two does not allow the one eating to
derive pleasure nor does it give him any benefit, and it is a long while before
he has enough; nor do the organs of taste or the stomach gain any pleasure by
such small morsels. To eat with five fingers and the whole hand causes the food
to crowd the organs and the stomach so the organs are forced to pass it
through, and the stomach to bear it. This gives neither pleasure nor relish.
The most excellent way of eating is that adopted by the Prophet and those who
follow him, with three fingers.
(Full article read here) http://www.healthymuslim.com/articles/fygxeafgd-eating-with-your-hands-has-amazing-health-benefits.cfm