Bejamin Natanyahu Speech before Congress- Something Strange...

This is the closing remark by Benjamin Natanyahu. What I found so strange was how the congress clapped at the end, never heard this before, it was strange. Throughout the whole speech the people clapped as they always do, but at the last minute after Benjamin Natanyahu blessed both Israel and the USA this happened and it was strange. Was it a sign of unity? The sound reminded me of a train, or when the people in the RNC shouted 'fight, fight, fight'. Listen all the way through. What do you think about this strange occurrence?