This philological commentary offers students a gateway to knowledge of Mishnaic Hebrew through study of Pirqe Avoth. It has enabled generations of students to unlock, with less pain and increased incentive, the language of the Rabbis as well as their mode of thinking and of operating. Students can use it to study on their own, and it is equally effective as a textbook or supplement in the classroom. The commentary covers differences between Biblical and Mishnaic Hebrew, helpful for students with some Hebrew background, as well as common idioms in rabbinic literature.