Just before Jesus taught the Lord’s Prayer, He made some mysterious statements.
“But when you pray, go into your room and shut the door and pray to your Father who is in secret. And your Father who sees in secret will reward you. And when you pray, do not heap up empty phrases as the Gentiles do, for they think that they will be heard for their many words. Do not be like them, for your Father knows what you need before you ask him.” (Mt 6:6-8 ESV)
Note that Jesus was not saying that we get a reward when we talk much while praying. What news, anyway, could surprise Him who is all-wise and all-knowing? However, Jesus promised a reward when we pray
(1) in our room
(2) shut the door and
(3) pray secretly