English Explanation of Pirkei Avot 3:13

Rabbi Akiva said:
Merriment and frivolity accustom one to sexual licentiousness;
Tradition is a fence to the Torah;
Tithes a fence to wealth,
Vows a fence to abstinence;
A fence to wisdom is silence.
Rabbi Akiva is arguably the most famous and influential rabbi in Jewish history. He was certainly the most influential rabbi in the mishnaic period. The Mishnah is based largely on his teachings, although most of them are attributed to his students.
There are numerous legends about Rabbi Akiva, perhaps the most famous one of them being that he did not begin to learn Torah until he was 40 years old. He died the death of a martyer when the Romans used a steel comb to flay his skin.
Merriment and frivolity accustom one to sexual licentiousness: one who acts with frivolity and is merry in the company of the opposite sex will eventually have sex with those with whom sex is prohibited (such as adultery).
Tradition is a fence to the Torah: according to most commentators this refers to the comments which were added to the text of Biblical books, and are meant to explain how the words are sometimes read in a manner different from the way that they are spelled. These comments act as a fence in the sense that they prevent misinterpretation of the Bible. The reason that they are called “tradition” is that they were preserved as traditions that were added to the Biblical text itself. [The Hebrew word for tradition is “masoret”. Those who eventually put down in writing all of these marks and fixed the “correct” readings for the Bible were called the Masoretes.]
Another explanation of this statement is that “tradition” refers to the Oral Torah, which was transmitted from generation to generation to teach us the correct interpretation of the Bible.
Tithes a fence to wealth: by properly tithing one’s produce one can ensure that he will grow rich. By extension, according to the rabbis, one who wanted to ensure that he would prosper should give more charity.
Vows a fence to abstinence: by taking vows a person can prevent himself from engaging in forbidden sex. If a person’s desires are strong, and he feels that he cannot overcome them, he may be better able to motivate himself and keep himself from sinning if he takes a vow not to do what is forbidden. In an interesting analogy, I know people who keep kosher who have no problem doing so but have terrible trouble sticking to their weight-loss diets. Sometimes, in order to more motivate themselves not to eat heavy dairy deserts they will eat a small piece of meat, thereby making it forbidden to eat milk afterwards. This is like the person who can only control his sexual desires if he takes a vow not to act upon them.
A fence to wisdom is silence: as we saw above in mishnah 1:17, one who tends to keep quiet will always at least seem wiser than one who can’t keep quiet. Also by being silent a person can actually hear what others are saying and thereby learn from them. According to a rabbinic teaching, this is why people were created with two ears and only one mouth, so that they could listen twice as much as they speak.