'Graft' in the Bible

Your rulers are rebels,friends of thieves.They all love graftand chase after bribes.They do not defend the rights of the fatherless,and the widow’s case never comes before them.

And even they, if they do not remain in unbelief, will be grafted in, because God has the power to graft them in again.

For if you were cut off from what is by nature a wild olive tree, and against nature were grafted into a cultivated olive tree, how much easier will it be to graft these who are the natural branches back into [the original parent stock of] their own olive tree?