Reference: Fataawa Noorun alad-Darb, Volume 1, Page 197
Question: A person saw some workers on his way to the masjid so he stopped by them and encouraged them to attend the salaah and gave them some advice. As a result of being delayed by the workers, he missed the Takbeeratul-Ihraam (the saying of Allaahu Akbar when beginning the salaah). So is he rewarded as one who caught the Takbeeratul-Ihraam or not?
Response: He is rewarded more than those who caught the Takbeeratul-Ihraam since being present for the Takbeeratul-Ihraam is a Sunnah. As for advising these [workers] and encouraging them with good, then that is obligatory. Therefore, he is rewarded more for this than having missed out on [the reward for attending] the Takbeeratul-Ihraam.