From Aleteia:
According to one Benedictine commentary, “After saying a prayer, then a person prayed in the heart and this was considered ‘prayer.’ So in some of the early traditions, after each Psalm there was a short period for this spontaneous cry from the heart to the Lord. It is this type of prayer that must be kept short and pure – and not prolonged because it really cannot be prolonged. Attempts to prolong such prayer are usually just show and not reality.”
St. Benedict wanted his monks to pray from their hearts and not to pray to gain attention from others. As he wrote in the same Rule, “We must know that God regards our purity of heart and tears of compunction, not our many words.”