Hadithcore
Riyad as-Salihin, 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)." <b>[Al-Bukhari and Muslim]</b>.

وعن ابن عباس رضي الله عنهما أن رسول الله صلى الله عليه وسلم قال‏:‏ ‏

‏لا يخلون أحدكم بامرأة إلا مع ذي محرم‏

‏ ‏(‏‏(‏متفق عليه‏)‏‏)‏‏.‏

References1 variant
In-Book Reference
Book 17, Hadith 119
Sharh · explanationclick to expand
<b>Guidance from the Hadith:</b><br> 1) It is prohibited for a man to be alone with a non-Mahram woman, for this is one of the instigators of corruption and falling into temptation and immorality.<br> 2) One has to keep away from the places of potential Fitnah and falling into sin, like unlawful intermixing and others.