Mishnah, — Seder Nezikin, Tractate Avot…
“ Also, weigh the loss [that may be sustained through the fulfillment] of a commandment against the reward [that may be obtained] for [fulfilling] it, And [weigh] the gain [that may be obtained through the committing] of a transgression against the loss [that may be sustained] by [committing] it. Keep your eye on three things, and you will not come into the grip of sin: Know what is above you: An Eye that sees, And an Ear that hears, And all your deeds are written in a book. ”
