Luke 1:59
And on the eighth day they came to circumcise the child, and were going to call him Zechariah, after his father.
Luke 2:21
When eight days had passed and the time for circumcising Him had come, He was called JESUS, the name given Him by the angel before His conception in the womb.
Philippians 3:5
circumcised, as I was, on the eighth day, a member of the race of Israel and of the tribe of Benjamin, a Hebrew sprung from Hebrews; as to the Law a Pharisee;
Acts 7:8
"Then He gave him the Covenant of circumcision, and under this Covenant he became the father of Isaac--whom he circumcised on the eighth day. Isaac became the father of Jacob, and Jacob became the father of the twelve Patriarchs.