3 Nephi 20:1

And it came to pass that he commanded the multitude that they should cease to pray, and also his disciples. And he commanded them that they should not cease to pray in their hearts.

Jesus told the crowd to stop praying out loud. He also told his disciples to stop. But he told them not to stop praying in their hearts.

He told the crowd and his disciples to stop praying out loud—but not to stop praying in their hearts.