Moth, rust and thieves
Moth, rust and thieves were the three insidious agents of the ancient world that could render the contents of a strongroom worthless. Most treasures were kept indoors, but even there insects and damp could penetrate. Dwellings were often built of relatively soft materials, so a determined thief could gain access by simply digging through the house wall.
(Matt 6:19-21 WEB)6:19 “Don’t lay up treasures for yourselves on the earth, where moth and rust consume, and where thieves break through and steal;
6:20 but lay up for yourselves treasures in heaven, where neither moth nor rust consume, and where thieves don’t break through and steal;
6:21 for where your treasure is, there your heart will be also.”
Where your heart is
The context here is coveting other people’s possessions and the antidote to that is generosity.
In Jesus’ day, treasure tended to take the form of fine clothing and metal objects. Being harder to produce than objects of wood and stone or agricultural produce they were of greater worth. Hence, gold and silver were precious, but even iron and fine cloth was very valuable.
In that period houses were generally constructed with windows on the first floor to keep thieves out, but walls were often less substantial than modern bricks and mortar, so thieves would break through them.
In Palestine, the fabric eating caterpillars of the moth Tineola bisselliella destroy fine clothing, whilst rust is the universal scourge of valuable iron tools. Thieves are less discriminating and may take anything of value. There is no treasure on earth so imperishable and so secure that it cannot succumb to the passage of time or be stolen away in some sudden disaster.
God’s presence ensures the absolute protection and preservation of heavenly treasure. However, such riches take a different form. Gold, silk and rubies are as worthless as common construction materials, for what God values above all else is character.
We all focus on those things that are important to us, so if our treasure is in Heaven our interest will be in Heaven as well. Some Jewish teachers spoke specifically of generosity as a way of laying up treasure in heaven. Certainly, as far as Heaven is concerned, generosity that reflects God’s nature out performs even the brightest of share portfolios.
. . . commentary continues with Matt 6:22-23