Psalms 50:18 - Matthew Poole's English Annotations on the Holy Bible

Sawest; or, didst observe, or consider; when he came into thy presence and company, and thou didst understand and consider his ways, and his success and impunity, and he invited thee to a participation of his profit. Thou consentedst with him; or, as many render it, then didst run with him; thou didst readily and greedily associate thyself with him in his unrighteous courses. Thou didst yield to his motions, and that with great complacency and diligence. Partaker with adulterers, by joining with them in their lewd and filthy practices.