Tafsir of Ghafir 40:68

He is the One who gives life [to the dead] and causes death [to the living], or He is the One who performs the act of giving life and causing death. So when He decrees a matter—meaning He intends for the manifestation of one of the affairs into external existence—He merely says to it, "Be," and it is.

[This occurs] without any dependence whatsoever upon any of the things [or causes]. According to the later scholars, this is a metaphorical representation of the effect of His power—Exalted is He—upon the decreed objects at the moment His will relates to them; it is an illustration of the swiftness with which created things follow His act of creation, without there being any commander or commanded [in the literal sense]. Discussion on this has already preceded.

The first fa (in "fa-innama") is to indicate that what follows it is a result of what preceded it, in the sense that it necessitates an essential power that is not dependent on numbers or intent. It is also permissible to consider it as explanatory (tafsiliyya) or causative (ta'liliyya). So, reflect upon this.