לעשות את השבת (כי תשא לא:טז)

The Gemara (שבת קי”ח) says: “כל המשמר את השבת כהלכתו, אפילו עובד עבודה זרה כדור אנוש מוחלין לו” – “Anyone who lawfully observes the Shabbos, even if he were to commit idolatry, it will be forgiven”.  This is alluded to in the acrostics (the first letter of each word) of the above pasuk: לעשות את השבת form the word אלה.  The phrase אלה was used by the Yidden to appoint their man-made idol during חטא העגל (the sin of the golden calf).  By keeping the laws of Shabbos, they are forgiven for this heinous sin!