Why did the Prophet allow the Companions to speak with his wives about matters such as a man having intercourse with his wife while she is menstruating? And why did the Companions ask the Prophet's wives about how he performed ghusl and about sexual matters instead of asking him directly? And why did he openly declare his love for Aisha? And what is the interpretation of that?

Aisha (may Allah be pleased with her) lived for approximately fifty years after the death of the Prophet (peace be upon him). She was the reference point for marital and purity matters. Examples of this include: Ubaydullah ibn Abdullah ibn Umar asking her about a man being intimate with his menstruating wife, and she permitted it. She also resolved the Companions' disagreement regarding the ruling on ghusl (ritual bath) after intercourse without ejaculation, clarifying that ghusl becomes obligatory when the circumcised parts touch.

As for Amr ibn al-Aas's (may Allah be pleased with him) question to the Prophet (peace be upon him) about the person he loved most, it is evidence of the virtue of those mentioned, and it shows the permissibility of mentioning love. The Prophet (peace be upon him) answered that it was Aisha, then her father Abu Bakr. Al-Qurtubi explained that this was due to following those whom the Prophet (peace be upon him) loved, and Aisha was mentioned first because her love was both natural (instinctive) and religious.