Wait for an appointed leader or imam to begin prayer first instead of starting on your own when praying in congregation .

This hadith tells us that it is not part of the sunnah to pray before the imam. The hadith was narrated by Tha'labah bin Zahdam and it was about 'Ali appointing Abu Mas'ud over the people and then going out on the day of 'Eid and saying that it is not part of the sunnah to pray before an imam. This means that when praying in congregation, one should wait for an appointed leader or imam to begin prayer first instead of starting on their own. This teaches us respect for authority figures as well as patience in waiting for others who may be leading a group activity or event.