In plain words
At the wedding, King Janaka had given Sītā a very precious pearl necklace. Sītā took off that pearl necklace and gave it to Hanumān.
You are the crest-jewel of monkey kings, who fulfilled the task of Raghupati; You are Hanumān the guru, who came forth in the worlds when sins had swelled; You are the hero of the great city, who entered the city of Laṅkā again and again; You are the one of great valour, who searched for Jānakī in every way; You are the crest-jewel of monkey kings, who fulfilled the task of Raghupati.
Saying, ‘You are the crest-jewel of monkey kings who accomplished Rāma's work; had it not been for you, Rāma's work would never have been done,’ she handed him that necklace. Everyone was watching. Hanumān broke it apart. Hanumān was biting each pearl and throwing it away. Sītā knew its inner meaning. But all the others there saw only the outside! ‘Yadbhāvaṃ tadbhavati.’ Each went on thinking according to his own feeling. ‘This is the monkey breed. However precious the things you give this monkey breed, they do not know their value. He is biting and biting these precious pearls and throwing them away; has this monkey nature not left him?’ some were thinking. To teach them all the right lesson, Sītā asked, ‘Hanumān! Why are you biting such precious pearls and throwing them away? Biting them, holding them to your ear, throwing them away: this is what you keep doing. Why are you doing this?’ ‘Mother! I am testing whether my Rāma's Name is in this pearl or not,’ said Hanumān. ‘Foolish one! Can Rāma's Name be in a pearl?’ Sītā asked again. ‘A pearl without Rāma's Name, however precious, is to me the same as useless stones. Any of the nine gems without Rāma's Name is to me no more than earth,’ Hanumān replied.