“completely filled.” The Hebrew text uses two nouns, “filled plenty,” which some versions translate as “filled with plenty.” We understood this to mean, “completely filled.” The Law of Moses commanded people to give a tenth of the grain they grew, as well as the other vegetable harvests such as grapes and olives (Lev. 27:30; Num. 18:21; Deut. 14:22). Animals were tithed also, but differently (Lev. 27:32). God promised that if Israel kept God’s commandments they would be blessed (Deut. 30:16; cp. Mal. 3:8-12).
This is one of the many “ideal” promises in the Word of God which would be fulfilled here on earth today if we lived in a godly world with godly people. We do not, and so there are people who honor God with their firstfruits who do not have full storehouses. There are many ungodly people who cheat and steal, and the Devil is the god of this age (2 Cor. 4:4; 1 John 5:19) so this promise will be fully fulfilled in the future.
[For more on promises like this, see commentary on Prov. 19:5. For more on tithing, see commentary on Deut. 14:22.]
“burst at the seams.” The Hebrew is more literally “burst open.”