Former neurosurgeon Ben Carson on Thursday explained that he had been following God's instructions when he shocked many people by calling for a flat tax at a non-partisan prayer breakfast with President Barack Obama last year.

During a 27-minute rant just feet away from the president at the National Prayer Breakfast, Carson had explained that Biblical “tithing” would make a better tax system. Fox News quickly heaped praise on Carson, while other conservative outlets like The Wall Street Journal and World Net Daily called for a presidential bid.

According to the Old Testament, Israelites were required by Mosaic law to support the priesthood by giving 10 percent of their land and livestock as a tithe, which is defined as a tenth of a person's income. Many Christians today have interpreted this to mean that they must give a flat 10 percent of their income to the church.

The so-called "flat tax," however, is generally considered to be regressive because it impacts poor people more than the rich.

And although the plan is almost exclusively supported by conservatives, Carson told CBN's Pat Robertson on Wednesday that "the Lord" told him to push for it at the non-partisan prayer breakfast.

"I realized that God probably had something special he wanted me to say," Carson explained. "But I didn't know what it was until the morning of the prayer breakfast."

"After a while of wrestling with it, I just said, I'm leaving it alone, the Lord will tell me what to say," he continued. "And that morning, it was so clear in my mind what I was supposed to say."

Carson insisted that he was not "attacking the president."

"You know, looking at our taxation system, how unjust it is," he opined. "And yet, we have people saying, 'Well, these people need to pay more.' I mean, what we need is something that hits everyone in an equal fashion, and that's why I brought up tithing from the Bible."

"You know, you make a lot, you pay a lot. You make a little, you pay a little. But you get the same rights. That's very just. What isn't just is you take half the people that don't pay any federal income tax, and you say you guys get to say on how much these other guys should pay. Come on, does that make any sense at all?"