Matthew 6:21 - Ellicott's Commentary On The Whole Bible

Where your treasure is. — The words imply the truth, afterwards more definitely asserted, that it is impossible to “serve God and mammon” (Matthew 6:24). Men may try to persuade themselves that they will have a treasure on earth and a treasure in heaven also, but in the long-run, one or the other will assert its claim to be the treasure, and will claim the no longer divided allegiance of the heart.