“The Messenger of
Allah
(ﷺ) used to gently pat our shoulders (to make sure the row was
straight) at the time of prayer, saying: ‘Keep (the rows) straight,
do
not differ from one another lest your hearts should suffer from
discord. Let those who are forbearing and wise stand closest to me,
then those who are next to them, then those who are next to them.’”
Sunan Ibn Majah Book 5, Hadith 174