Chazal say that Avraham exemplified the midah of “emor m’at v’aseh harbei” as we see from this week's parsha where he offered to serve the angels a bite of bread and then brought out a whole gourmet fleishig seudah. Ephron, in next week’s parsha, exemplifies the opposite, as we see from his at first passing off Avraham’s offer to buy Me’aras haMachpeila as a trifling and then collecting full price for it.
Lichorah this idea of “emor m’at” is simply a hedge against getting caught in a lie. Don’t promise too much, because in the end, you may not be able to deliver. Circumstances arise… things happen. However, Avos D”R Nosson (ch 13) writes that even Hashem practices this midah: Avraham was told in last week’s parsha , “V’gam es hagoy asher ya’avodu dan anochi” – just 2 letters, daled-nun – and the Egyptians in the end were punished with miracles and miracles. Hashem, according to the Avod D”R Nosson, deliberately did not mention the full measure of punishment that would be brought upon Egypt because Hashem is “omeir m’at.” In the Shiurei Da’as, in a shiur written over by my wife’s grandfather, R’ Bloch asks: if “emor m’at v’aseh harbei” is just a hedge against not being able to fulfill your promise, then what sense does it make for Hashem to practice this midah? Hashem is kol yachol and can do anything, and He knows in advance all the circumstances and obstacles that stand in the way of something being accomplished. Surely he needs no hedge against not being able to carry out what he says!
A strong question, no? I don't think I can do justice to the answer.