How did Baochai collar come from?

It was given by the monk. When Baoyu was born. They managed to throw the psychic Baoyu into his mouth. It is engraved with the seal script "Don't forget, don't forget, present Heng Chang". To prove the theory of good marriage. So he gave Baochai a gold collar. It is also engraved with the seal script of "Never leave, never leave, never leave, never stay young". In this way, two verses are beyond gold and jade. It just confirms good luck.