But if they obey not - This also is a general rule, from which, in the course of Providence, there are only few, and those only apparent, deviations. Instead of they shall perish by the sword, the meaning of the Hebrew בשלח יעברו beshelach yaaboru, is, "By a dart they shall pass by." They shall be in continual dangers, and often fall before they have lived out half their days. Mr. Good translates: They pass by as an arrow. The Vulgate: Transibunt per gladium. "They shall pass away by the sword."

if

Deuteronomy 18:15 The LORD your God will raise up to you a Prophet from the middle of you, of your brothers, like to me; to him you shall listen;

*etc:

Deuteronomy 29:15-20 But with him that stands here with us this day before the LORD our God, and also with him that is not here with us this day...

Isaiah 1:20 But if you refuse and rebel, you shall be devoured with the sword: for the mouth of the LORD has spoken it.

Isaiah 3:11 Woe to the wicked! it shall be ill with him: for the reward of his hands shall be given him.

Romans 2:8,9 But to them that are contentious, and do not obey the truth, but obey unrighteousness, indignation and wrath...

perish. Heb. pass away. die

Job 4:21 Does not their excellency which is in them go away? they die, even without wisdom.

John 8:21-24 Then said Jesus again to them, I go my way, and you shall seek me, and shall die in your sins: where I go, you cannot come...

Whether the Old Law was from God?
Objection 1: It would seem that the Old Law was not from God. For it is written (Dt. 32:4): "The works of God are perfect." But the Law was imperfect, as stated above [2060](A[1]). Therefore the Old Law was not from God. Objection 2: Further, it is written (Eccles. 3:14): "I have learned that all the works which God hath made continue for ever." But the Old Law does not continue for ever: since the Apostle says (Heb. 7:18): "There is indeed a setting aside of the former commandment, because of the …
Saint Thomas Aquinas—Summa Theologica

Divine Grace.
GRACE, LOYE, AND MERCY. I FIND that the goodness of God to his people is diversely expressed in his word, sometimes by the word grace, sometimes by the word love, and sometimes by the word mercy. When it is expressed by that word grace, then it is to show that what he doeth is of his princely will, his royal bounty, and sovereign pleasure. When it is expressed by that word love, then it is to show us that his affection was and is in what he doeth, and that he doeth what he doeth for us with complacency …
John Bunyan—The Riches of Bunyan

Messiah's Easy Yoke
Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls. For my yoke is easy, and my burden is light. T hough the influence of education and example, may dispose us to acknowledge the Gospel to be a revelation from God; it can only be rightly understood, or duly prized, by those persons who feel themselves in the circumstances of distress, which it is designed to relieve. No Israelite would think of fleeing to a city of refuge (Joshua 20:2. …
John Newton—Messiah Vol. 1