“Three times a year all your males shall appear before the presence of Hashem your G-d” (Devarim 16,16)
It is a positive commandment that every male must appear in Jerusalem in the Beis Hamikdash at three specific times every year and they are Pesach, Shavuos and Sukkos. Concerning this it says “Three times a year all your males shall appear before the presence of Hashem your G-d”. The point of the commandment is that every man with all his male progeny, as soon as they reach the age where they can walk unaided to the Beis Hamikdash, must go up to the Beis Hamikdash and show himself there. Included in this appearance is that he must offer a burnt offering there and this offering is termed “the offering of appearance”. This offering has no measure, even one pigeon or chick will fulfil his obligation.
Amongst the roots of the commandment: In order that all of Israel will see and absorb into their hearts the act of the sacrifice which arouses hearts. Since all of them, from the smallest to the biggest, are the portion of Hashem and His inheritance, a holy and chosen people, who form His testimony, the treasure of all the nations who exist under the heavens, to keep His statutes and perform His law, therefore they should come to the House of the L-rd three times a year. By doing so they are stating: Here we are as slaves to G-d, entering and coming under the shelter of His doorway and in His jurisdiction, relying forever on love of Him and fear of Him, and no stranger can come into our midst, for we alone are the members of His household. Through this pilgrimage, our intellect will awaken and we will enter the fear of Him into our hearts, and we will fix His love in our ideas and we will merit to receive His kindness and His blessing.