Rav Elimelech Biderman (Torah Wellsprings, parashas Devarim - Tishah B'av 2017, p. 16) quotes the Kotzker Rebbe and says that whoever studies sefer Devarim, becomes close(r) to Hashem.
"Even a Yid [RebYehudi] who isn't close [semuchim]to Hashem the entire year,can become close to Hashem when he studies chumash Devarim."
In what context is the Kotzker Rebbe teaching this idea? What exactly does he say and why especially focused on sefer Devarim? (Please include original location of source from Kotzker, since I haven't found it using the words on Otzar HaChochmah).
Any ideas where this can be found and why he writes this?