Riyad as-Saliheen 1629
Ibn Abbas (May Allah be pleased with them) said:
The Messenger of Allah ﷺ said, "No one of you should meet a woman in privacy unless she is accompanied by a Mahram (i.e., a relative within the prohibited degrees)."
[Al-Bukhari and Muslim].
وعن ابن عباس رضي الله عنهما أن رسول الله ﷺ قال:
"لا يخلون أحدكم بامرأة إلا مع ذي محرم" ((متفق عليه)).
Classification
Sahih (Authentic)
References
Riyad as-Saliheen 1629
Riyad as-Saliheen Book of Prohibited actions, Hadith 119