Charles Ellicott Commentary Deuteronomy 6:5

"and thou shalt love Jehovah thy God with all thy heart, and with all thy soul, and with all thy might." — Deuteronomy 6:5 (ASV)

With all your heart, and with all your soul, and with all your might. —The word “heart” has been taken both as “thought” and “affection.” Hence, perhaps, the four terms, “heart, mind, soul, and strength,” which we find in Mark 12:30.

Bashi says upon the expression “all your heart”—“with both natures” (the good and evil nature). “With all your soul” he expounds thus: “Even though He take it (your life) from you.” And “with all your might” he paraphrases in a truly practical and characteristic fashion, “With all your money, for you sometimes find a man whose money is dearer to him than his life (or body).” Or, as an alternative, “in every condition which He allots to you, whether prosperity or chastisement.”

And so He says in David, I will take the cup of salvation (deliverances), and I will call on the name of the Lord (Psalms 116:13); and again. I shall find trouble and heaviness, and I will call on the name of the Lord (Deuteronomy 6:3–4). It is an interesting illustration of the passage, though the verbal connection on which it is based will not hold.