פירוש על קידושין 33:13

As stated above, Rabbi Shimon derives the amount the master must give the slave from the use of the word “giving” in both this context and in the context of dedicating the value of something to the Temple. The highest value is 50 shekels.
But why not learn from the lowest value—which is 5 shekels?
Again, the Talmud answers with the verse “as the Lord God blesses you.” This is read as mandating a higher amount.