Where in the world do they get that the Bible say that it's ok to hit your wife?!?! That goes against everything the Bible teaches about showing love and respect to each other! That's ridiculous.
Eph 5:25 Husbands, love your wives, just as Christ loved the church and gave himself up for her
Eph 5:33 Nevertheless, each individual among you also is to love his own wife even as himself, and the wife must see to it that she respects her husband.
1 Pet 3:7 "In the same way, you husbands must give honor to your wives. Treat your wife with understanding as you live together. She may be weaker than you are, but she is your equal partner in God’s gift of new life. Treat her as you should so your prayers will not be hindered."