At twilight on the eve of Passover God’s people were instructed to mark their doors with blood. God said, “When I see the blood, I will pass over you.” It was a foreshadowing of the mercy that was to come for all those “under” the covering of the blood of the Jesus.
Ezekiel 9 tells of another marking that God instructed. It’s a story of a city under siege, yet the people refuse to turn to God their only source of salvation. Angelic guards were called forward and with them came another angel carrying a writing kit. This heavenly scribe is told to search throughout the people and mark only those that grieve and lament over all the detestable things that are done. The guards followed him with destruction, and only those with the mark were passed over. How’s that for a picture of a guardian angel?