According to my knowledge, even in Christianity, the Divine messenger , archangel, Gabriel was depicted in Human form with wings. So we cannot restrict this depiction to Hinduism alone.
Coming to the question part - "how did the rishis/munis who wrote Vedas/Purans after listening to Ākāśavāni predicted how a ...
“Think of the universe as an ocean of ether, consisting of layer after
layer of varying degrees of vibration under the action of Prana; away
from the centre the vibrations are less, nearer to it they become
quicker and quicker; one order of vibration makes one plane. Then
suppose these ranges of vibrations are cut into planes, so many
millions of ...
Bhagavad Gita 7.25
नाहं प्रकाशः सर्वस्य योगमायासमावृतः ।
मूढोऽयं नाभिजानाति लोको मामजमव्ययम् ॥
I am never manifest to the foolish and unintelligent. For them I am
covered by My internal potency, and therefore they do not know that I
am unborn and infallible.
According to Shankara, this verse states about the reason ...
A true rishi is one who is a devotee of lord also. Spiritual path is a heart to heart connection. So the lord reveals himself to his devotee in heart. Citing this verse from Srimad Bhagvatam 10.86.47
हृदिस्थोऽप्यतिदूरस्थ: कर्मविक्षिप्तचेतसाम् ।
आत्मशक्तिभिरग्राह्योऽप्यन्त्युपेतगुणात्मनाम् ॥ ४७ ॥ But although You
reside within the heart, You ...
It’s One aspect of Shiva called Vamadeva is responsible for veiling. It’s part of panchanana functions the five-fold functions of Shiva. Hiding knowledge that you have learnt at appropriate times or let it flow to your Jivatma. Of course that is delegated to Shanishwara mostly...it is in almost all Shaiva scriptures.. lookup