Is the greeting of the mosque obligatory or recommended?

The Shaykh : He says: Is the greeting of the mosque obligatory or recommended?
The opinion that it is obligatory is undoubtedly strong, and it is strengthened by the fact that the Prophet (peace and blessings be upon him) was delivering the sermon when a man entered and sat down, so he said: He ordered him to occupy himself with the prayer of two rak'ahs instead of the obligatory act of listening to the sermon, and one cannot be occupied with something other than an obligation except by another obligation. Then his statement (peace and blessings be upon him): This is a prohibition, but there are specific cases that support the opinion of the majority, which is that the greeting of the mosque is a recommended practice (sunnah) and not obligatory. Therefore, we see that the precaution and the safest course for the conscience is that a person should not leave it.