Behold, I will send to you Elijah the prophet, before the arrival of the great and terrible day of the Lord
Other versions
King James Version
Behold, I will send you Elijah the prophet before the coming of the great and dreadful day of the LORD:English Standard Version
"Behold, I will send you Elijah the prophet before the great and awesome day of the LORD comes.New International Version
"See, I will send you the prophet Elijah before that great and dreadful day of the LORD comes.