The Messenger of Allah ﷺ said, "Straighten the rows, align your shoulders, close the gaps, be gentle in the hands of your brothers, and do not leave openings for the devil. Whoever joins a row, Allah will join him, and whoever cuts off a row, Allah will cut him off."
أن رسول الله ﷺ قال: أقيموا الصفوف، وحاذوا بين المناكب، وسدوا الخلل، ولينوا بأيدي إخوانكم، ولا تذروا فرجات للشيطان، ومن وصل صفا وصله الله، ومن قطع صفا قطعه الله.
Abu Dawud (666) reported it, "Isa bin Ibrahim Ghafiqi told us, Ibn Wahb told us." Another chain, "Qutayba bin Saeed told us, Layth told us," and the hadith of Ibn Wahb is more complete, "from Muawiya bin Salih, from Abu Zahiriya, from Kathir bin Mura, from Abdullah bin Umar," and he mentioned something similar. This is a sahih, connected isnad.Qutayba said, "from Abu Zahiriya, from Abu Shajara," without mentioning Ibn Umar, "that the Messenger of Allah ﷺ said, 'Straighten the rows, align the shoulders, close the gaps, and yield gently to the hands of your brothers.'" Isa did not say, "to the hands of your brothers."Abu Dawud said, Abu Shajara is Kathir bin Mura.I say, this isnad is disconnected, being a mursal report, but it does not defect the first isnad, since it is known in the sciences of hadith that an addition from a reliable narrator is accepted.Abu Dawud said, the meaning of "yield gently to the hands of your brothers" is that when a man comes to the row intending to enter it, each man should relax his shoulders for him so that he may enter the row. End of quote.Nasai (819) reported it from Isa bin Ibrahim bin Matrud, who said, "Abdullah bin Wahb, from Muawiya," with it, in shortened form, "Whoever joins a row, Allah joins him, and whoever cuts off a row, Allah cuts him off ." Its isnad is sahih.Abu Zahiriya is Hudayr bin Kurayb Al-Himsi. Ibn Main, Nasai, and Ajli deemed him reliable, and Abu Hatim said, "There is no harm in him," so by right he should be considered reliable, and he is among the narrators of Muslim, though the Hafiz placed him at the rank of "saduq."Ibn Khuzayma also graded it sahih, reporting it in his Sahih (1549) from Isa bin Ibrahim Ghafiqi with it, in shortened form, like Nasai's version, and Hakim (1/213) reported it through other routes from Ibn Wahb, saying, "Sahih according to the standard of Muslim."