ERC20 token contract: does approve function need to check caller balance?

Question

I'm reading ERC20.sol source code. There's a question about the approve function.

function _approve(
    address owner,
    address spender,
    uint256 amount
) internal virtual {
    require(owner != address(0), "ERC20: approve from the zero address");
    require(spender != address(0), "ERC20: approve to the zero address");

    _allowances[owner][spender] = amount;
    emit Approval(owner, spender, amount);
}

In the function, it requires owner != address(0) and spender != address(0). I just wonder should we do the amount check in the function? Such as:

require(amount <= _balances[owner]);

Thanks.