In this Hadith, brevity of prayers stands for recitation of short Surah of the Noble Qur'an in prescribed congregational prayers. The Sahih Muslim has elucidated this by saying that the Prophet (PBUH) would recite short Surah on hearing the crying of a baby. In short, this Hadith mentions that affection which he had for his followers. Its importance can be judged by the fact that he made a demonstration of it even in the prescribed prayers.