romans 11:16 For if the firstfruit be holy, the lump is also holy: and if the root be holy, so are the branches. - Free Bible Online

      16. For--"But"
      if the first-fruit be holy, the lump is also holy; and if the root . . . so the branches--The Israelites were required to offer to God the first-fruits of the earth--both in their raw state, in a sheaf of newly reaped grain (Le 23:10, 11), and in their prepared state, made into cakes of dough (Nu 15:19-21) --by which the whole produce of that season was regarded as hallowed. It is probable that the latter of these offerings is here intended, as to it the word "lump" best applies; and the argument of the apostle is, that as the separation unto God of Abraham, Isaac, and Jacob, from the rest of mankind, as the parent stem of their race, was as real an offering of first-fruits as that which hallowed the produce of the earth, so, in the divine estimation, it was as real a separation of the mass or "lump" of that nation in all time to God. The figure of the "root" and its "branches" is of like import--the consecration of the one of them extending to the other.

JFB.