Asalaam alaikum, as for the questions you have posted i will try to clarify it a bit more so that you can have a better understanding, insha Allah.
before dealing with the details i believe it is more important that we should understand the word 'wahi' first. as it is an arabic word and english is not as rich a language as arabic, sometimes we find it difficult to translate let alone understand.
Wahi is the Arabic word for revelation and it is derived from the arabic word 'ahwa'. The word awha (أوحى awḥá) occurs in a number of shades of meaning, each of them indicating the main underlying idea of directing or guiding someone or something.
"...and inspired in each heaven its command," (Quran 41:12)
"And your lord inspired to the bee," (16:68)
"And we inspired to the mother of Moses," (28:7)
there are literal meanings for the word 'wahi' too, Inspiration, revelation, suggestion, to point out a thing to someone, to put a thing into the mind of someone secretly; letter, writing: something revealed or written or the idea inspired or revealed; saying; commandment; to dispatch a messenger to someone; to speak with ...
there are mainly two types of wahi,
Wahee-e-Matlu: It means the revelation which God has transmitted in His own words and speech, for example the Quran
Wahee-e-Ghair Matlu: It is the revelation which Allah projected in the heart of the Holy Prophet
keeping all this in mind, ill try to elaborate on the questions you have asked.
i do not have an answer for this part of question yet.(because i don't fully understand your question)
"It is not fitting for a man that Allah should speak to him except by inspiration, or from behind a veil, or by the sending of a messenger to reveal, with Allah's permission, what Allah wills".[42.51]
this verse lays the foundation for understanding 'wahi'.based on this verse islamic scholars have described three ways in which Allah's revelation can reach the chosen individuals, especially the prophets.
- An inspired message – not a word but an idea – can enter the heart of the chosen individuals either in the state of consciousness or in dream.
- The second mode, it is said, is the word heard by the person spoken to, like, from behind a veil.
- In the third mode, the revelation is sent from Allah through archangels like jibreel and is delivered to the prophets. It is the highest form of revelation, the whole Quran was revealed in this mode.
and now to discuss about normal human beings receiving 'wahi' (revelation), I'll quote from the quran;
Indeed, [O Muḥammad], you do not guide whom you like, but Allah guides whom He wills. And He is most knowing of the [rightly] guided. (58:56)
For indeed, Allah sends astray whom He wills and guides whom He wills. (35:8)
there are numerous ways in which Allah guides someone to the straight path, in the life of a person though he/she may not comprehend it at first, Allah is always showing you signs and guiding you. it's not that angels would come with the messages for us but there would be ways in which we are guided, we just dont know it.
Abu Hurairah (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) said, "All that is left from Prophethood is the glad tidings." He was asked what the glad tidings were, and he said, "The good dream."
Reference : Riyad as-Salihin 837
as for the second part of your question about the unseen, i am afraid to answer as i do not know what you mean by the unseen. are you referring to the ghayb or something else?.
No one knows the unseen in the absolute sense except Allah!
“Say: “None in the heavens and the earth knows the Ghaib (Unseen) except Allaah, nor can they perceive when they shall be resurrected”
[al-Naml 27:65]
“And with Him are the keys of the Ghayb (all that is hidden), none knows them but He. And He knows whatever there is in the land and in the sea; not a leaf falls, but He knows it. There is not a grain in the darkness of the earth nor anything fresh or dry, but is written in a Clear Record”
[al-An’aam 6:59]
it would be much easier if you could have used the arabic word instead of the word 'unseen', as ghayb and unseen is also different in certian context. Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said in Sharh al-‘Aqeedah al-Waasitiyyah (p. 158): What is meant by the unseen is that which is not seen. The unseen is something relative. But that which is unseen in the absolute sense (al-ghyab al-mutlaq) is known only to Allah.and also i would like to mention one more verse from the glorious quran,
(He Alone is) the All‑Knower of the Ghayb (Unseen), and He reveals to none His Ghayb (Unseen)
[al-Jinn 72:26].
- i believe the answer to this question is there in my introduction and in the answer to the second part of your question.
i hope my feeble effort may bring you closer to a clearer understanding and may Allah grant you mercy and guide you to the straight path.
Allah knows best.