And she vowed a vow, and said, O LORD of hosts, if thou wilt indeed look on the affliction of thine handmaid, and remember me, and not forget thine handmaid, but wilt give unto thine handmaid a man child, then I will give him unto the LORD all the days of his life, and there shall no razor come upon his head. (1Sa 1:11)
Most adherents of the Futurist interpretation do not even have a clue as to where the seven year tribulation is derived from in the scripture itself, though it happens to be the host period of every key event that differentiates their view from the historical position.
There are two foundational scripture passages upon which the seven year tribulation is based:
Paul, an apostle of Jesus Christ by the will of God, and Timothy our brother, unto the church of God which is at Corinth, with all the saints which are in all Achaia: Grace be to you and peace from God our Father, and from the Lord Jesus Christ. Blessed be God, even the Father of our Lord Jesus Christ, the Father of mercies, and the God of all comfort; (2Co 1:1-3)
editing by R. James Gill
For more details get the book:
The Rapture will be Canceled
What Year is It?