(Ez. 1:15) And behold one wheel on the earth next to the ‘angelic-beasts’∞ḥayot... This is the point under the segol ֶ, the point that is below, next to the ḥayot which are tzerei ֵ, (Gen. 1:16)... the two great luminaries...
And so it is in the midst of the ophanim – shureq וּ. One ophan (wheel) above, and one ophan below – and the Middle Pillar, it is between them.
And behold one wheel on the earth... (Ez. 1:16) – this is ḥireq ִ, which is below.
Each ‘spark’ is a י Yod, and each ‘firmament’ is a ו Vav.