The Midrash compares Avram to a sealed bottle of perfume that Hashem removed the seal from, shook up and permeated the world with. Next we observe that the constraint was Avram's own doing. The boundaries were his own self imposed boundaries. I have taught others to be kind and considerate. Normally self imposed boundaries like drinking, eating, working, resting and temperament, etc. are often good.
Boundaries often represent protection and comfort.
However in Avram's situation boundaries were stifling. It seems Avram's self imposed boundaries were out of respect to G-d in honor of his father. Avram inclumbered his life with more fences than he needed. This fastidiousness was inhibiting Hashem's purpose for his life. This is an indiscretion baal teshuva's often make in there zealousness to emulate Hashem.