Note 3 at 1 Cor. 9:9: This phrase is a quotation from Deuteronomy 25:4 and is quoted two times in the New Testament (1 Cor. 9:9; 1 Tim. 5:18). Paul is describing a Hebrew cultural practiceof threshing grain. For example, corn or some other grain would be laid flat on the floor while an ox would be driven over the stalks, shaking the corn loose from its husks. It would then be separated from the chaff. It was prohibited by the Law of Moses to muzzle the oxen's mouth during this process. The ox was free to eat from the stalks as he worked. Paul uses this Old Testament illustration to point out the right of Christian ministers to reap carnal thingsas they have sown spiritual things.

Note 4 at 1 Cor. 9:9: The point that Paul is making is that God is much more concerned about us than He is the animals. And there are many scriptures that speak of His care for the animals (Dt. 5:14; Ps. 145:15-16; 147:8-9; Mt. 6:26; Lk. 12:24).