01. Likutei Sichos – Vol 16 p 231 ff. – Tosfos Shabbos, Class One.

01. Likutei Sichos – Vol 16 p 231 ff. – Tosfos Shabbos, Class One.
The Mechilta and the Gemara both hold and prove ‘Tosfos Shabbos’ (adding before and after the actual times of Shabbos, Yom Kippur and Yom Tov) from different sources.
They agree about Yom Kippur and Yom Tov; but Shabbos the Mechilta supports from (another source) זכור ושמור that there are both a positive and a negative aspects.
The source the Gemara brings, establishes Tosfos Shabbos the act of Yidden; while the Mechilta’s idea (on Tosfos Shabbos) makes it ‘Cheftza’: the Shabbos itself adds the holiness to the minutes before and after.