15-16 You shall not give up to his master a slave who has escaped from his master to you.  He shall dwell with you, in your midst, in the place that he shall choose within one of your towns, wherever it suits him. You shall not wrong him.

17-18  None of the daughters of Israel shall be a cult prostitute, and none of the sons of Israel shall be a cult prostitute. You shall not bring the fee of a prostitute or the wages of a dog into the house of the Lord your God in payment for any vow, for both of these are an abomination to the Lord your God.

19-20 You shall not charge interest on loans to your brother, interest on money, interest on food, interest on anything that is lent for interest. You may charge a foreigner interest, but you may not charge your brother interest, that the Lord your God may bless you in all that you undertake in the land that you are entering to take possession of it.

21-23 If you make a vow to the Lord your God, you shall not delay fulfilling it, for the  Lord your God will surely require it of you, and you will be guilty of sin. But if you refrain from vowing, you will not be guilty of sin. You shall be careful to do what has passed your lips, for you have voluntarily vowed to the Lord your God what you have promised with your mouth.

24-25  If you go into your neighbour's vineyard, you may eat your fill of grapes, as many as you wish, but you shall not put any in your bag. If you go into your neighbour's standing corn,  you may pluck the ears with your hand, but you shall not put a sickle to your neighbour's standing corn.” Deuteronomy 23: 15-25 English Standard Version

Moses now gives the Israelites some general rules by which they would not only avoid doing things that would grieve God's Spirit, but would also promote compassion in their community. When vs 15-16 speaks of a runaway slave we shouldn't think of the barbaric conditions in which Africans were shipped to Europe and America in the 18th century. Slaves in Israel were more like servants and many loved their masters. So if one ran away it's very likely it was because of harsh, perhaps even cruel, treatment. It may even be that the slave had run away from one of the pagan nations around them. Whatever the case, they were to take pity on the runaway and give them refuge.

The cult prostitutes of vs 17-18 were people involved in sexual practices associated with the worship of pagan gods. It seems that even after being rescued there were people among the Israelites who were still attracted to customs they’d known in Egypt, and practices they saw in the land to which God was bringing them. The apostle Paul had to deal with a similar issue in Corinth where some Christians thought they could still visit pagan temple where cult prostitution took place. Christians today can apply this to what ‘entertainment’ we watch.

In vs 19-20 they were taught to be generous and helpful to one another. There was a brotherly love among them which ought also to be true of Christians today. What was a good reason Moses gave them in those verses for practicing that sort of generosity?

It would result in God's blessing in all they undertook. God blesses kindness. But they were also to be careful of making rash gestures of kindness. (vs 21-23) If they promised anything to the Lord they were to be careful to do what they promised. Do we sometimes make little promises to God in our thoughts and then, later on, forget to do them?

What would you say was the message of vs 24-25?

They were not to be free loaders. They were not to exploit the generosity of others. At the same time the verses also teach that the owners of the vineyards and cornfields were not to be misers. They were not to be angry if someone in need took something for their hunger. If you put together all the things today’s verses touched on you'd find that they tell us something about God.

He is a compassionate God, and He is holy. He is also generous and someone who keeps His word. He doesn't make empty promises. And He is certainly not a miser. He gives in abundance. Our job is to seek to reflect His character to others.