This then explains the ten saplings which are connected to the seventh year which refers to the drawing down and revelation of the ten supernal Sefiros into the supernal state of Malchus.
This is also what the Possuk is referring to when it says וַיִּטַע אֶׁשֶׁל בִּבְאֵׁר שָבַע “Avrohom Ovinu planted an ‘Eishel’ in Be’er Sheva”. Because the basic understanding of the word Eishel is a single tree (As the Iben Ezra writes as well as other Torah commentators who explain the Possuk) that it refers to the Ze’eir Anpin of the spiritual world of Atzilus which represents the growth of Atzilus and it includes all of the ten supernal Sefiros of the spiritual world of Atzilus which are the ten saplings.
Regarding the difference between the spiritual ascension of the worlds on Shabbos to the spiritual ascension of the worlds in the sabbatical year of Shmittah. The abounding secret that the Arizal reveals to us is regarding the ascension of the worlds to their source because the first ‘six units’ are about descent and the seventh is about elevation. This is true in days as it is in years, because this is the way that HaShem extended vitality to the six days of creation and on the seventh day He rested. Like the Possuk states “HaShem saw everything that He had done, and it was ‘Tov Me’od’’ and then ‘Vayechulu’ He concluded the heavens and the earth and all their hosts”. This means that it was very good for Him Blessed Be He that which He concluded the heavens and earth. But here the word ‘Vayechulu’ has another connotation from the expression ‘Kolso Nafshi’ meaning a yearning of the soul. In other words, the worlds were created in a way that they ascend again after all the days of the cycle. And they ascend with a yearning of the soul to their root and source and this is very good for HaShem Blessed Be He because as a result of this ascent they receive light and vitality from the source of the elixir of life Blessed Be He. So as to continue to influence thereafter in the days of their descent. And so, this cycle repeats continuously until Moshiach comes when tranquillity will vitalise the worlds. Now, according to the degree of the ascension so is the sanctity of the day. Like on Shabbos where the ascension is greater therefore all work is forbidden whereas on Yom Tov, certain Melochos i.e. cooking food are permitted. And then on Chol Hamoed even works which if not done would cause a serious loss are also permitted. And on Shmitta only working the ground is forbidden.
Seventh year: like the words of the Mishnah that is quoted above.
