Land patent grant 1860 for heirs to perpetuity

what does it mean to heirs that the land that was granted to a great great great grandfather to his heirs or apigne (this word was hard to read) for ever, the great great great grandfather deed to grandfather in the grandfathers will it says, i bequete to my wife and her heirs all my land, and then the grandmother sold it, so what does the heirs for ever mean on the grant or to perpetuity, when does that wording end, in the grandfathers will it was listed as separate property, but she sold it in 1966, was that ok to sell, what is the difference in land patent and fee simple toward the heirs

Are you sure that it didn't say heirs and assigns?

I may be showing a huge lack of experience, but I don't know what "apigne" could mean. Usually a grant is to "heirs and assigns forever" meaning that the land is granted to the grantee or anybody they either convey interest to or to their heirs forever.