Musar do Hioba 17:6

The letters of the Ineffable Name spelled in words יוד-הי-ויו-הי, total 72 in numerical value, as does a different kind of spelling called גלגול י-ה-ו-ה י-ה-ו י-ה י. This combination too totals 72. In that combination the first name symbolizes the original Existence, the mystery of G–d's Essence, the second three-lettered name which totals 21 symbolises that G–d created the universe out of "nothing," and the fact that He existed independent of such a universe. The name א-ה-י-ה which also totals 21, being a form of the future tense, tells us that in the future G–d will reveal Himself. The name י-ה, is also used in the past tense in Job 17,6 "ותפת לפנים אהיה," "I have become like Tophet of old." This means that the name א-ה-י-ה i.e. the "three-lettered name י-ה-ו," is a development of the original four-lettered name. The name י-ה is employed to remind us of how G–d guides history and the fate of man through the system of reward and punishment. A typical example is Psalm 130,3: אם עונות תשמר י-ה מי יעמוד? "If You keep account of sins, O Lord, Lord who will survive?" Another well known example of the use of that two-lettered name of G–d is Psalms 118,18: יסר יסרני י-ה ולמות לא נתנני, "The Lord punished me severely, but did not hand me over to death." On the other hand, the same name is used when discussing man's reward, such as in acknowledging Israel's salvation from the pursuit of the Egyptians in Exodus 15,2: עזי וזמרת י-ה ויהי לי לישועה, "The Lord is my strength and might; He is become my deliverance." Another example is Psalms 118,5: מן המצר קראתי י-ה ענני במרחב י-ה, "In distress I called on the Lord; the Lord answered me and brought me relief."