It is written
It is written
Every single time a New Testament author says "This is what is written", he goes ahead to quote a statement from the Old Testament.
See Matthew 2:5-6
Matthew 4:4
Matthew 4:6
Matthew 4:7
Matthew 4:10
Matthew 11:10
Matthew 21:13
Matthew 26:31
Mark 1:2
Mark 7:6-7
Mark 11:17
Mark 14:27
Luke 2:23
Luke 3:4-6
Luke 4:4
Luke 4:8
Luke 4:10-11
Luke 7:27
Luke 19:46
Luke 20:17
Luke 22:37
John 2:17
John 6:31
John 6:45
John 12:14-15
Acts 13:33
Acts 15:17
Acts 23:5
Romans 1:17
Romans 2:24
Romans 3:4
Romans 3:12
Romans 4:17
Romans 8:36
Romans 9:13
Romans 9:33
Romans 10:15
Romans 11:8
Romans 11:27
Romans 12:19
Romans 14:11
Romans 15:3
Romans 15:9
Romans 15:21
1 Corinthians 11:19
1 Corinthians 1:31
1 Corinthians 2:9
1 Corinthians 3:19
1 Corinthians 9:9
1 Corinthians 10:7
1 Corinthians 14:21
1 Corinthians 15:45
1 Corinthians 15:54
2 Corinthians 4:13
2 Corinthians 48:15
2 Corinthians 9:9
Galatians 3:10
Galatians 3:13
Galatians 4:27
Hebrews 10:7
1 Peter 1:16