The hadith regarding the two rak'ahs for one who enters while the imam is delivering the sermon, and the greeting of the mosque

Question:
What is the authenticity of the hadith in which it is mentioned that the Prophet (peace and blessings be upon him) ordered a man to pray two rak'ahs on Friday when he wanted to sit down? And if it is authentic, how do we reconcile it with your honorable opinion that the greeting of the mosque is not obligatory?

Answer:
Yes, his ordering the man to pray two rak'ahs is not from the category of obligation, but rather from the category of recommendation. So, if one enters while the imam is delivering the sermon, he prays two rak'ahs as the greeting of the mosque. Even if he sits down and does not pray, he is not a sinner who commits a sin by doing so, because the greeting of the mosque is absolutely recommended, but it becomes more emphasized for the one who enters while the imam is delivering the sermon. As for it being obligatory, that is not the case, as evidenced by the statement of the Bedouin .
So, in the hadith, it is "except if you volunteer." This includes the greeting of the mosque absolutely, whether one enters while the imam is delivering the sermon or not. The Messenger (peace and blessings be upon him) did not make it obligatory except if one enters while the imam is delivering the sermon, in which case it is obligatory upon him. He did not explain this to the Bedouin.