Hadithcore
Riyad as-Salihin, 592

Hasan bin 'Ali (May Allah be pleased with them) reported:

I have retained these words of Messenger of Allah (ﷺ), "Leave what causes you doubt and turn to what does not cause you doubt." <b>[At- Tirmidhi, who classified it as Hadith Hasan Sahih]</b>.

وعن الحسن بن على رضي الله عنهما، قال‏:‏ حفظت من رسول الله صلى الله عليه وسلم‏:‏ ‏

‏دع ما يريبك إلى ما لا يريبك‏

‏ ‏(‏‏(‏رواه الترمذى وقال‏:‏ حديث حسن صحيح‏)‏‏)‏‏.‏

References1 variant
In-Book Reference
Introduction, Hadith 592
Sharh · explanationclick to expand
<b>Guidance from the Hadith:</b><br> 1) Do not act except on what you believe to be certain or most likely. As for doubt, it is not a basis for rulings in the Shariah.<br> 2) The believer should stop at suspicious matters and avoid them so that he can base his religion on what is clear and certain.