Priests should keep their homilies short and speak for a maximum of eight minutes to prevent members of the congregation from nodding off, Pope Francis said on Wednesday.
The homily, or message delivered by a celebrant during a church service, "must be short: an image, a thought, a feeling", the pope said during his weekly audience.
It should not last longer than eight minutes "because after that time attention is lost and people fall asleep, and they are right," said the 87-year-old pontiff.
"Priests sometimes talk a lot and you don't understand what they are talking about."
A homily in a Roman Catholic service usually follows a reading from the Bible and is used to reinforce the teaching.
Francis has spoken in the past of the need for priests not to ramble on in their homilies but his own use of language is currently under scrutiny.
He has caused controversy with reports that he has used a highly derogatory term to describe the LGBT community.
Francis apologised last month after Italian media attributed to him the use of the word "frociaggine", a vulgar Italian term roughly translating as "faggotness" or "faggotry" on May 20 during a closed-door meeting with Italian bishops.
However, according to Italian news agency ANSA, Francis repeated the term on Tuesday as he met Roman priests.
