src/Components/Validation/Validation.php
public function rule($field, $label, $rules, array $text = [])
    {
        $this->labels[$field] = $label;
        $this->rules[$field] = $rules;
        $this->texts[$field] = (! empty($text) ? $text : null);
    }
public function rule($field, $label, $rules, array $text = [])
    {
        $this->labels[$field] = $label;
        $this->rules[$field] = $rules;
        $this->texts[$field] = (! empty($text) ? $text : null);
    }
Define One Validation Rule

@param string $field
@param string $label
@param string $rules
@param array  $text

@return void