Jesus’ disciples had just gone through radical surgery, the crucifixion of their friend, teacher and Lord. Though the shock had numbed them, it was starting to wear off. They were awakening from the stupor and the pain was hitting them with full force. Good News was coming: the surgery was successful, the Lord was alive. But as with many surgeries, a sign of recovery was post-operative pain; for them, spiritual heartburn (v.32)! 
Scripture:  Luke 24:13-15