'Certain' in the Bible

There was a certain man without a dependent, having neither a son nor a brother, yet there was no end to all his labor. Indeed, his eyes were not satisfied with riches and he never asked, “And for whom am I laboring and depriving myself of pleasure?” This too is vanity and it is a grievous task.

Sow your seed in the morning and do not be idle in the evening, for you do not know whether morning or evening sowing will succeed, or whether both of them alike will be good.

Rejoice, young man, during your childhood, and let your heart be pleasant during the days of young manhood. And follow the impulses of your heart and the desires of your eyes. Yet know that God will bring you to judgment for all these things.