Seven. Denotes spiritual perfection. It is the number or hall-mark of the Holy Spirit's work. He is the Author of God's Word, and seven is stamped on it as the water-mark is seen in the manufacture of paper. He is the Author and Giver of life; and seven is the number which regulates every period of Incubation and Gestation, in insects, birds, animals, and man.
Eight. Denotes resurrection, regeneration; a new beginning or commencement. The eighth is a new first. Hence the octave in music, color, days of the week, &c. It is the number which has to do with the LORD, Who rose on the eighth, or new "first-day". This is, therefore, the Dominical number. By Gematria (see above), 'JJjjIhsous (Jesus) makes the number 888. It, or its multiple is impressed on all that has to do with the Lord's Names, the Lord's People, the Lord's works.
(Number in Scripture' by E.W. Bullinger)