These words can be, and have been, applied to some of the great
saints of Islam, who were certainly not prophets, because they possessed
some qualities of prophets such as communication from Allah
(in the limited form in which it is promised to true believers by
the Holy Quran and Hadith).
These words (rasul, nabi) are used by way of metaphor,
just as in Hadith also the word nabi has been used for
the Promised Messiah. It is obvious that he who is sent by God
is His envoy, and an envoy is called rasul in Arabic. And
he who discloses news of the unseen, having received it from God,
is known as nabi in Arabic. The meanings in Islamic terminology
are different. Here only the linguistic meaning is intended.
(Arbain, published December 1900, No. 2, p. 18,
footnote. Ruhani Khaza’in, vol. 17, p. 366)
Here the words rasul and nabi which have
been used about me in the revelation from God, that he is the
messenger and prophet of God, are meant in a metaphorical and
figurative sense.
(Arbain, No. 3, p. 25, footnote. Ruhani Khaza’in, vol. 17, p. 413)
God speaks to, and communicates with, His saints (auliya)
in this Ummah, and they are given the colour of prophets.
However, they are not prophets in reality (haqiqat).
(Mawahib ar-Rahman, published January 1903, pp. 66–67. Ruhani Khaza’in, vol. 19, p. 285)
And I have been called nabi (prophet) by Allah by
way of metaphor, not by way of reality (haqiqat).
(Haqiqat al-Wahy, Supplement, p. 64. Ruhani Khaza’in, vol. 22, p. 689)