A South Canterbury man told a judge at the Timaru District Court the Bible justified caning his children.

A born-again Christian defending his bamboo canings says his faith taught him to hit his children's bottoms when they misbehaved.

The South Canterbury man, whose name is suppressed, faces charges of assault with a weapon.

He says his hyperactive son needed the punishments.

"I follow the Bible and the Bible overrules those laws, I'm afraid," the man said of the Crimes Act in the Timaru District Court on Friday.

Under cross-examination from police prosecutor Simon Heeley, the man said giving his children repeated canings was "not my way, it's God's way".

"Well, was God doing it, or was it you doing it?" Heeley asked.

"I don't know if that's a fair question," the man said.

"Well, who was in there hitting him with a stick?" Heeley asked.

"I was," the man replied.

Defence lawyer Jay Lovely said section 59 of the Crimes Act, which Parliament amended in 2007 to prevent parents using force to correct children, still allowed parents to use reasonable force to prevent children "engaging or continuing to engage in disruptive behaviour".

Heeley argued the law did not allow the canings.

The man, who the court heard rediscovered his Christian faith in 2014, told Judge Joanna Maze he wanted to give his son "a lasting impression of the discipline that I was giving him".

The court heard the boy, 13, had been stood down and expelled from schools several times. Poking holes in a plant worth $2000 led to one of his canings in July 2015, the man said.

The man feared his son would "end up being a career criminal" without his discipline regime, which he said included confiscations of playthings.

"I love my kids. I want them to be Christian as well," he said.

His son, who chose to make an affirmation rather than a bible witness oath, said his father cried when he hit him.

Heeley asked if the man eschewed "politically correct" disciplinary practices and preferred to follow the biblical rule of "spare the rod and spoil the child".

"I don't believe that's written anywhere in there," the man said.

"Our Bible we follow, it's not the Good News version," he explained, glancing at a courtroom copy, "it's the King James version. It's the best doctrinary Greek bible that you can get."

Proverbs 13:24 in the King James states "he that spareth his rod hateth his son: but he that loveth him chasteneth him betimes".

The man told the court he chose to use a cane because "I don't want my kids being scared of my hands when I give them a cuddle".

However, in a recording of a telephone call with his former partner after she saw marks on her son's bottom, he could be heard saying he used the cane to avoid hurting his hand.

The man's former partner said her son had been diagnosed with attention deficit hyperactivity disorder, and she later learned the man had taken her son off his medication.

The judge declined to make a decision on Friday, and remanded the man on bail to appear on June 23.