Of old time I have broken thy yoke - It is thought by able critics that the verbs should be read in the second person singular, Thou hast broken thy yoke, Thou hast burst thy bonds; and thus the Septuagint, συνετριψας τον ζυγον σου, "thou hast broken thy yoke." And the Vulgate, Confregisti jugum meum, rupisti, vincula mea; "Thou hast broken my yoke; thou hast burst my bonds;" and so the Arabic. But the Chaldee gives it a meaning which removes the difficulty: "I have broken the yoke of the people from thy neck; I have cut your bonds asunder." And when this was done, they did promise fair: for "thou saidst, I will not transgress;" but still they played the harlot - committed idolatrous acts in the high places, where the heathen had built their altars, pretending that elevation of this kind assisted their devotion.
Transgress - Rather, as in marg. If the “yoke” and “bands” refer to the slavery in Egypt from which Yahweh freed Israel, the sense is - “For of old time I Yahweh broke thy yoke, I burst thy bands,” not that thou mightest be free to do thy own will, but that thou mightest serve me: “and thou saidst, I will not serve.”
When - “For under every leafy tree thou” layest thyself down as a harlot. The verb indicates the eagerness with which she prostrates herself before the objects of her idolatrous worship.