'Saith' in the Bible

I am the Alpha and the Omega, saith the Lord God, he who is, and who was, and who is to come, the Almighty.

And to the angel of the assembly in Sardis write: These things saith he that has the seven Spirits of God, and the seven stars: I know thy works, that thou hast a name that thou livest, and art dead.

And to the angel of the assembly in Philadelphia write: These things saith the holy, the true; he that has the key of David, he who opens and no one shall shut, and shuts and no one shall open:

And I heard a voice out of the heaven saying, Write, Blessed the dead who die in the Lord from henceforth. Yea, saith the Spirit, that they may rest from their labours; for their works follow with them.