Is it permissible to exchange greetings (Salām) in the mosque while the Qur’an is being recited or while the Imam is delivering the sermon?

One who attends the Friday prayer must listen attentively to the sermon. It is forbidden to speak during it, except for what the evidence has exempted, such as the speaker addressing the congregants and vice-versa, for a need or benefit, like the Imam speaking to address a technical issue with the loudspeaker. The prohibition includes answering a jurisprudential question, saying "Yarhamukallah" to someone who sneezes, and returning greetings. The Prophet, peace and blessings be upon him, said: "If you say to your companion while the Imam is delivering the sermon on Friday, 'Listen,' you have indeed spoken idly."