Al-Hasan ibn ‘Ali ibn Abi Tālib reported that the Prophet (may Allah's peace and blessings be upon him) said: "Leave what you doubt to what you do not doubt.''
شرح الحديث :
The believer should leave off anything that one doubts as being impermissible, so that one may not commit something that is forbidden, without noticing it. Rather one should discard doubtful things and instead go for things which are certainly lawful, so that one's heart is at peace. With this, one will be interested in pure lawfulness, staying away from prohibitions, doubtful things, and uncertainties.