《资治通鉴·唐纪·唐纪二十一》
上面放置涂金铁凤，高二丈，后来被大风损坏；另造铜火珠，由群龙捧着，定名为通天宫。
上施金涂铁凤，高二丈，后为大风所损；更为铜火珠，群龙捧之，号曰通天宫。
A gold-plated iron phoenix was placed on it, which was two zhang high. Later, it was damaged by strong winds; another copper fire bead was made, held by dragons, and named the Palace of Heaven.