Having written "Veyadata ha'Yom," What do we learn from "va'Hashevosa el Levavecha"?
Chafetz Chayim (Z'chor le'Miryam 21): "Veyada'ata" is to clarify the truth in the mind; "Va'hashevosa el Levavecha" is to fix the matter in the heart, and fulfill it in practice, 1 as the Torah writes in Eikev, 11:18
Knowledge with the mind is insufficient. If one does not take the lesson to heart, the heart (alias the Yeitzer ha'Ra) will override one's knowledge, as the Gemara says in Sanhedrin, 106b 'Rachmana Liba Ba'i' - See Rashi there.
Lev Eliyahu (Sh'mos p.155): R. Yonah lists after this Mitzvos Aseh of remembering Hashem's Chesed, fearing Him, loving Him, and clinging to Him. Through contemplating His greatness and remembering His Chesed, one comes to fear, from fear to love, and from love to Devekus.
What are the connotations of "Ein Od"?