JMNT(i)
9 Jesus decidedly replied, "Are there not twelve hours [in] the day (= of daylight)? If anyone may habitually walk around (= live his life) within the Day, he does not constantly stumble (cut toward or strike against [something]), because he continually sees (looks at; observes) the Light of this world (of this cosmos; this system's light; or: = because he progressively perceives the light and understanding that guides this System and secular society).
10 "Yet, if anyone should habitually walk around within the Night, he constantly stumbles (strikes against [things]), because the Light is not (does not exist) within him."