(Exodus 23:14) "Three festivals shall you celebrate for Me in the year": What is the intent of this? Because it is written (Ibid. 17) "Three times, etc.", I might think at whatever place or time that one wishes; it is, therefore, written (Devarim 16:16) "on the festival of Matzoth, and the festival of Shavuoth, and the festival of Succoth." (Exodus 23:17) "shall be seen" (yod, resh, alef, heh, [which can also be read as "shall see"])