Expositor's Bible Commentary Commentary Mark 13:31

"Heaven and earth shall pass away: but my words shall not pass away." — Mark 13:31 (ASV)

The certitude and absolute reliability of Jesus’ words (esp. in v.30) are far greater than the apparent continuance of the entire universe (implied by the words “heaven and earth”). It will someday pass away, but Jesus’ words will always have validity (cf. Psalms 102:25–27; Isaiah 40:6–8; Isaiah 51:6).

Jesus’ call for vigilance pervades this paragraph—“Be on guard! Be alert!” (v.33); “Therefore keep watch” (v.35); “do not let him find you sleeping” (v.36); and “Watch!” (v.37).