Charles Ellicott Commentary Matthew 6:21

"for where thy treasure is, there will thy heart be also." — Matthew 6:21 (ASV)

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