Jewish figure of Speech concerning One day as a thousand yearsA common saying among the Jews, founded on the same passage, (Mynv Pla hb "qh) (lv wmwy) , "the day of the holy blessed God is a thousand years" this phrase should be thought to refer, as it is by some, to the day of judgment, and be expressive of the duration of that: it is certain that the Jews interpreted days of millenniums, and reckoned millenniums by days, and used this phrase in confirmation of it. Thus they say (F1), ``in the time to come, which is in the last days, on the sixth day, which is the sixth millennium, when the Messiah comes, for the day of the holy blessed God is a thousand years.'' And a little after, ``"the Lord hath created a new thing in the earth, a woman shall compass a man". This is in the time of the Messiah which is in the sixth day.'' (6000th )And elsewhere (F2,) ``the sixth degree is called the sixth day, the day of the holy blessed God is a thousand years. And in that day the King Messiah shall come, and it shall be called the feast of gathering, for the holy blessed God will gather in it the captivity of his people.'' So they call the sabbath, or seventh day, the seventh millennium, and interpret( F3) ``"the song for the sabbath day", (Psalms 92:1) title, for the seventh millennium, for one day of the holy blessed God is a thousand years.'' To which agrees the tradition of Elias, which runs thus (F4) ``it is the tradition of the house of Elias, that the world shall be six thousand years, two thousand years void (of the law), two thousand years the law, and two thousand years the days of the Messiah;'' for they suppose that the six days of the creation were expressive of the six thousand years in which the world will stand; and that the seventh day prefigures the last millennium, in which will be the day of judgment, and the world to come; for ``the six days of the creation (they say ) is a sign or intimation of these things: on the sixth day man was created; and on the seventh his work was finished; so the kings of the nations of the world (continue) five millenniums, answering to the five days, in which were created the fowls, and the creeping things of the waters, and other things; and the enjoyment of their kingdom is a little in the sixth, answerable to the creation of the beasts, and living creatures created at this time in the beginning of it; and the kingdom of the house of David is in the sixth millennium,answerable to the creation of man, who knew his Creator, and ruled over them all; and in the end of that millennium will be the day of judgment, answerable to man, who was judged in the end of it; and the seventh is the sabbath, and it is the beginning of the world to come.''............................................One Day of God is 1000 years a millenium this is Jewish Idiom (figure of speech) that was in common useby Rabbinical Jews of Jesus day a week would be spoken as 7,000 years (7 millenium) this is used in terminology of Genesis and the Lords Day 1000 years (one millieuim) .. also see 2 Peter 3:8
