And Aaron's sons shall burn it on the altar
 That is, the fat of the several parts before mentioned; this signified the sufferings of Christ, by which our peace is made, and by whose death we are reconciled to God: this rite of burning the fat of the inwards of sacrifices was used by the Pagans, and is still retained by the idolatrous Indians to this day F8: 
 upon the burnt sacrifice;
 which, as Gersom says, was the burnt offering of the daily sacrifice of the morning, which was offered first of all sacrifices; so Jarchi says, 
``we learn that the daily burnt offering preceded every other offering:''this was an eminent type of Christ's sacrifice:
 which is upon the wood that [is] on the fire;
 that is, which burnt offering was laid upon the wood on the fire, and the fat of the peace offering upon that: 
 [it is] an offering made by fire, of a sweet savour unto the Lord;
 as Christ's sacrifice is, ( Ephesians 5:2 ) (See Gill on Leviticus 1:9).