Based on:  Luke 19:39-40 (NIV)

Some of the Pharisees in the crowd said to Jesus, “Teacher, rebuke your disciples!” 

“I tell you, “He replied, “if they keep quiet, the stones will cry out.”

Excerpt:

As Jesus approaches Jerusalem those who had seen the miracles he had performed, and no doubt those who had just heard about his mighty works; began to praise God. The whole crowd began to praise God with joy. The scripture says they began to praise God, “…in loud voices.”