One Bad Quality Can Spoil Numerous Good Ones

It is reported that ʿUmar b. Al-Khaṭṭāb – Allāh be pleased with him – said to a young man while exhorting him:

A man might have ten qualities, nine of them good and one bad, but the nine good ones can be spoiled by the one bad quality. Beware of the slips and faults of youth.

ʿAbd Al-Razzāq Al-Ṣanʿānī, Al-Muṣannaf 8240.