It is known that the creation of the world and all it's creations are thru the Sefira of Malchus. Thru S. of Malchus Hashem gives chayos to the world and all the creations, like it is written,Malchuscho Malchus kol oilomim . The reason is because, Hashem kavayochel, Olo Birtzoinoi the inyan of Melucha. So from this Meluchscho comes Malchus kol Oilomim, all the worlds created.
So we understand from this that the entire inyan of all creations, worlds etc..is only a ray , which is the inyan of Melucha, which is an extension - extension shows that it is a ray.
As we see b'gashmius, a king in his country, whether it is in big cities where big people run the place or small cities where not such big people run it also in towns and villages, so every law that pertains to the country and its inhabitants is done according to the leadership of the king. Everything, everywhere in the entire country is done in the name of the king, so when the leaders say something in the name of the king everyone stands with kovad as if the king himself was here. It's not that the king is everywhere, it is only the NAME of the king, the name of the king is spread all over, extended all over the country.
The same thing here, we will understand in Sefiras Hamalchus, that it is only an extension , we say, Melech Shmoy nikro Alayhem, the citizens of a country are not the king's children, it is only that his name is on them.The same in Sefiros Hamalchus, that it is only a ray, therefore Sefiros Hamalchus is called Dibbur Ho-elyoin.