There’s a peledik (amazing) Medrash Tanchuma

as follows: Hashem said to Avrohom, “You told them ‘noh,’ therefore, I will give to your children the mitzvah of Korban Pesach (sacrifice of the Pascal lamb) with the specification of not to eat it ‘noh’ (raw).” What makes it amazing is that the two words have no connection to each other. Noh as used by Avrohom means please or now, e.g. “please let water be brought” or “let water be brought immediately” while, as before, by the Korban Pesach it means raw.

The Maharal states

that all the laws regarding Korban Pesach are to show the “oneness” of Hashem. Some examples – when eating the korban one should not break any bones – making two out of one. You can only eat in one house, not partly in house A and the rest in house B. The lamb must be consumed entirely. Therefore, if a whole lamb is too much for one family, you make a chaburah, a group. You cannot eat it partly in this group and partly in another group. You cannot boil it in liquid since boiling tends to separate pieces. Therefore, one shall not eat it raw because “through roasting it the juice and liquids will drip out and the meat will solidify and become completely one.” Therefore, it is prohibited to eat it raw because by roasting it he shows more the oneness of Hashem.

Washing of the Feet

The reason that Avrohom told them to wash their feet was because in those days there were people who used to bow down to the dust of their feet

“and he was assiduous not to bring idols (the dust) into his house.”

This then is the connection between the two “nohs.” Indeed, they are two different words (albeit the same spelling). However, since Avrohom was assiduous on the oneness of Hashem (through the word “noh”) his children merited the mitzvah of “noh” regarding the Korban Pesach. That is, not to eat it “noh” thereby showing the oneness of Hashem.

Over the Counter

When I told this vort (Torah thought) to one of the Roshei Yeshiva at Ner Yisroel he countered that the Medrash implied that because of Avrohom’s use of “noh” some new ground was broken by giving us the mitzvah of “noh.” However, according to the above answer only an addition was given to an already substantial list of mitzvos promulgating the Oneness of Hashem.

I countered that new ground was indeed broken. All the other injunctions specified that one should not make two or more out of that which was one. However, regarding the mitzvah of “noh” (raw) you already have one piece. Nevertheless, the one piece is composed of meat and juices. The mitzvah here is to accentuate the oneness by making it, so to speak, more one. That is, to remove the juices and have only the meat itself. This more elevated and specified concept of oneness is what Avrohom merited by his assiduousness of not permitting idols in his house.