Were customs dues levied at the time of the prophet Muhammad?

The levying of customs was common in pre-Islamic Arabia. They were usually levied in the annual fairs and in Mecca, where Muhammad's ancestor, Qusayy, reportedly levied them from the non-Meccans entering Mecca. Muhammad conti nued this age-old practice, hence the phrase la yu'sharuna wa-la yuhsharuna in his letters to certain parties. It exempted these parties from the paym ent of customs, while all the others had to pay up.