There is no agreement in narrations as to the exact length...
There is no agreement in narrations as to the exact length of time he had to wait, when the moments of inspiration were stilled. Some have cited it as 12 days, some 15 days, some 19 days, some 25 days and some forty days. Some narrations also denote that it was only for 2-3 days. The Prophet promised to be blessed to his heart's content. At the beginning of the Surah, again, we are faced with two oaths sworn to the Light and sworn to the Night, saying: "By the Glorious Morning Light".
"And by the Night when it is still". The term /duha/ means the beginning hours of the day when the sun rises high in the sky and it brightens up everywhere. This is, in fact, the best time of day or, in other words, it is the youth of the day. At this time of day, in summer, the heat of the sun is not so tormenting, and in winter, it has defeated the coolness of the weather, and it is at this time that we are, both bodily and spiritually, full of energy ready to do whatever we need to do.
The term /saja/ is derived from /sajw/ and originally means 'to be quiet, tranquil'; and it has also been used with the meaning of 'to cover, to darken' but, here it confers the meaning of 'quietness' and 'tranquility', hence, on the nights when the wind does not blow the terms; laylatun- sajiyah; 'a quiet night', and for the sea, with the lack of any storm and roaring waves, the term /bahrun saj/ ‘the quiet sea' are used in the Arabic language.
In any case what is important about 'night' is its peace and stillness which naturally gives tranquility to Man's nerves and makes him prepared for his next day's struggles or days of spiritual life and work. From this point of view 'night' is very important and it deserves to be sworn to. There is a close similarity and relationship between these two oaths and their contents.
The 'Glorious Light' of the day is, metaphorically, the descent of the revelations to the holy heart of the Prophet (S), and the stillness or quiescence of the night is compared to the days and periods of waiting for revelation, which is sometimes necessary in some cases. Then, following these two great oaths, it refers to the conclusion and the response of the oaths and says: "Your Lord has neither forsaken you nor has He become displeased".
The term /wadda'a/ is derived from /taudi/ which means 'to leave'. The term /qala/ is based on /qila/ in the sense of 'hate and enmity", and is derived from the root /qalw/ meaning 'to throw'.