The Mishna on today’s daf teaches that when taking the kometz – the fistful of flour – from a meal offering, it must be done properly. The Mishna offers a list of situations that are considered to be improper and would render the offering invalid. These include a non-priest, a priest who was in mourning or was not wearing the official priestly robes, who had not washed his hands and feet, or who was uncircumcised or ritually defiled, or who was sitting at the time or who removed the handful with his left hand. The Mishna continues that if when taking the kometz he picked up a small stone or a grain of salt or a drop of frankincense it also invalidates the offering, since he has taken “too little”.
The reason for this last rule is that the kometz has a specific size that must be taken – the fist of the kohen – and if he picks up a foreign substance it is clear that he has taken less than the full amount of the required kometz.
The frankincense mentioned is the levona that is required for the incense in the Temple. It is identified as the resin that oozes from a certain type of tree – the boswellia – that grows in eastern Africa and on the Arabian peninsula. Some suggest that it is boswellia sacra from southern Arabia or boswellia frereana that grows in eastern Africa. When the bark of these trees is cut, the resin that leaks out hardens and becomes solid frankincense. This frankincense was used as incense from ancient times, and it was also used for medicinal purposes. It was burned as incense by itself or combined with other ingredients.
It is identified in the Bible as coming from the land of Sheba (see Sefer Yeshayahu 60:6). Depending on the type and quality of the tree from which the levona was extracted, different grades of frankincense were produced. The finest frankincense is referred to in the Bible as levona zaka – “pure frankincense.”