Four things come not back: the spoken word, the spent arrow, the past, the neglected opportunity.

The saying is a compact moral lesson about irreversibility. Words, once spoken, cannot be unsaid; an arrow, once released, cannot be recalled; time past cannot be recovered; and chances ignored often do not return in the same form. By grouping these together, the proverb urges restraint in speech and action, attentiveness to the present, and decisiveness when opportunity appears. Its parallel structure and concrete images (word/arrow) make an abstract point—human agency has limits once a threshold is crossed—while the final item, “neglected opportunity,” shifts from fate to responsibility: regret is frequently self-made through inattention or delay.