This tradition has also ben transmitted by Anas through a different chain of transmitters. This version goes:
when the Messenger of Allah ﷺ stood for prayer, he took it (the stick) in his right hand and turning (to the right side) said; keep straight and straighten your rows. He then took it in his left hand and said; keep straight and straighten your rows.

حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا حُمَيْدُ بْنُ الأَسْوَدِ، حَدَّثَنَا مُصْعَبُ بْنُ ثَابِتٍ، عَنْ مُحَمَّدِ بْنِ مُسْلِمٍ، عَنْ أَنَسٍ، بِهَذَا الْحَدِيثِ قَالَ إِنَّ رَسُولَ اللَّهِ ﷺ كَانَ إِذَا قَامَ إِلَى الصَّلاَةِ أَخَذَهُ بِيَمِينِهِ ثُمَّ الْتَفَتَ فَقَالَ " اعْتَدِلُوا سَوُّوا صُفُوفَكُمْ " . ثُمَّ أَخَذَهُ بِيَسَارِهِ فَقَالَ " اعْتَدِلُوا سَوُّوا صُفُوفَكُمْ " .