Why was "Awḥī ilayya" not extended with a separate madd in Surat al-Jinn, as "yahdī ilā ar-rushd" was extended?

The Almighty's saying, "أُوحي إليَّ" (It was revealed to me), does not contain a madd (lengthening), because the yaa' (ي) is unani-mously vowelled with a fat-hah (أُوحيَ) by all reciters. It is the lam al-fi'l (the third radical) of a past tense verb built on a fat-hah.