1 Corinthians 9 : 7 Who goeth a warfare any time at his own charges? who planteth a vineyard, and eateth not of the fruit thereof? or who feedeth a flock, and eateth not of the milk of the flock? 8 Say I these things as a man? or saith not the law the same also? 9 For it is written in the law of Moses, Thou shalt not muzzle the mouth of the ox that treadeth out the corn. Doth God take care for oxen?

Paul again here is emphasizing how important it is that the minister of God should be provided for by the church he is ministering to. In the world when we work at a job we expect to get paid for the work we do by the people we did the work for, not obtain great wealth but to receive what we deserve for the job done. The same is true for the minister he is not in it to get rich but to receive what is expected for the services rendered. This was even true in biblical times, the  priest lived of of what was brought into the temple. In verse 9 when  he speaks of the ox it is really talking the men who labor for the Lord and how God will see they are taken care of.  We should always take care of the the people minister to us in any way we can, whether it be with money or goods.