A.T. Robertson Commentary Mark 12:41

"And he sat down over against the treasury, and beheld how the multitude cast money into the treasury: and many that were rich cast in much." — Mark 12:41 (ASV)

Sat down over against the treasury (καθισας κατεναντ του γαζοφυλακιου). The storm is over. The Pharisees, Sadducees, Herodians, scribes, have all slunk away in terror ere the closing words. Mark draws this immortal picture of the weary Christ sitting by the treasury (compound word in the LXX from γαζα, Persian word for treasure, and φυλακη, guard, so safe for gifts to be deposited).

Beheld (εθεωρε). Imperfect tense. He was watching

how the multitude cast money (πως ο οχλος βαλλε) into the treasury. The rich were casting in (εβαλλον, imperfect tense) as he watched.