In the time of the Second Temple the Pharisees and Sadducees were in conflict on many issues. One of the most dramatic involved the date of Shavu’ot.
According to the Pharisees, the seven weeks leading up to Shavu’ot began on the second day of Pesach, since they interpreted the verse, “On the morrow of the day of rest”, as referring to the Pesach festival. The Sadducees said that “day of rest” had its normal meaning of Shabbat, and began counting on the first Sunday of Pesach.
The Biblical passage at issue is Lev. 23:11-16, where the word Shabbat actually comes three times. If the Pharisaic interpretation is accepted, Shabbat means a different thing each time – “festival”, “week”, and “Sabbath”. Is it logical that a word can have three meanings?
The Pharisees’ view recognises linguistic history and says “yes”. In English, take the word “man”, which is sometimes “a male” and sometimes “humanity”. Take the word “day”, sometimes “24 hours”, sometimes “an era”. It all depends on the context.