There's an additional detail in the apocryphal story. The king and the Parsis didn't have a language in common. The king was reluctant to allow them to settle.

There's an additional detail in the apocryphal story. The king and the Parsis didn't have a language in common. The king was reluctant to allow them to settle. To communicate this, he dops a few pebbles into a container full of milk which promptly overflows. The implication being that the kingdom was full. The Parsis then mix sugar into the milk implying they would assimilate.