Then the devil took Him into the holy city; and he had Him stand on the pinnacle of the temple, and said to Him, "If you are the Son of God throw yourself down. For it is written, 'He will give His angels charge concerning you,' and, 'On their hands they will bear you up, lest you strike your foot against a stone." - Matthew 4:5-6
The second temptation
Satan took Jesus to Jerusalem to stand on the temple. There Satan challenged Jesus to throw himself down. Although the exact spot is not given, Josephus recorded that Herod's royal portico towered 450 feet over the Kedron Valley (Antiquities XV.412).
Satan quotes scripture
Having lost the first challenge, Satan appeals to scripture by quoting Psalm 91:11-12. When isolated from other passages, this proposal seems reasonable. If Jesus were God's Son, then scripture promised to save Him.
Deceptively, Satan tried inciting Jesus to test the scripture. Jesus addressed the real issue by quoting Deuteronomy 6:16.
Jesus said to him, "On the other hand it is written, 'You shall not put the Lord your God to the test.'" - Matthew 4:7
To commit this act would have tested God, not scripture. Putting God to the test does not refer to an exam. Rather, the idea of "experimenting with God" is contained in this phrase.
Had He fallen to this temptation, Jesus would have substituted humble faith in God's guidance with a blatant challenge to the Father's lovingkindness. God protects His children, but also expects them to exercise sound judgement.