If we hear someone say salawat by mentioning Prophet Muhammed (صلى الله عليه واله وسلم), is it obligatory to send salawat as we heard his name in their salawat. I’m sorry if the question is confusing.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

Sending Blessings and Peace of Allah upon the Prophet when hearing his name, is a matter upon which the scholars differed in opinion about its ruling. Ibn al-Qayyim said in his book Jala’ al-Afham fi Fadhli as-Salaat ‘ala Muhammad Khayrul-Anam:

“They [the scholars] differed about its obligation whenever his name is mentioned. Abu Ja’far at-Tahawi and Abu ‘Abdullah al-Hulaymi said: It is obligatory to send Blessings and Peace of Allah upon him whenever his name is mentioned, and others said that it is desirable and not an obligation for which a person is sinful if he does not do it.” [End of quote]

For more benefit on the virtues of invoking blessings upon the Prophet, please refer to Fatawa 86784, eighty times on Friday">307192, 248305 and 246610.

Allah knows best.