This statement is true.
When making foreign trading policies, things like tariffs decide how many things will be imported from where. If you have a most favored nation, you give them lower tariffs and thus motivate them to trade more with you and you help their economy. There can also be an opposite when you make tariffs higher for someone in order to reduce their importing.
In general, silk was most likely was Persia’s most valuable asset. It was silk and similar entities that were traded by Persians along the infamous Silk Road, which connected the far East with Europe. Persia was in an advantageous position right in the middle.
