What is the Sharia ruling on some people's objection to the segregation of men and women in a da'wah gathering at the mosque, claiming that circumstances in America are different and that Islam does not prohibit it, along with a request for Sharia evidence on the necessity of segregation? And what are the Sharia guidelines for such gatherings?

The truth lies in the necessity of gender segregation, because the prevalent mixing nowadays makes it difficult to comply with Allah's command to lower one's gaze, as stated in His words: (Tell the believing men to lower their gaze and guard their private parts. That is purer for them. Indeed, Allah is Acquainted with what they do. And tell the believing women to lower their gaze) [An-Nur: 30-31]. This aligns with the directives of the Prophet, peace be upon him, as exemplified by Ibn Umar, may Allah be pleased with both of them, and with the distinction between rows of women and men during his era and the era of the Rightly Guided Caliphs.