in his sharh salam e raza, mufti muhammad khan qadri writes that this description of laylat al-qadr for the darkness of the blessed forelocks and maTla' al-fajr for the parting in the blessed hair is the genius of alaHazrat and alaHazrat hi ka hissa hai.
imam baraylawi says: laylat ul qadr meiN maTlayil fajr haq maang kee istiqaamat pe lakhoN salam at first glance, one thinks this couplet is about laylat al qadr in ramadan [that has just passed a few nights ago]. but, what the imam means is that the parting in the blessed hair of the prophet sallAllahu 'alaihi wasallam is like the rising sun [tulu' e fajr / maTlayil fajr] after the night of laylat al qadr [the dark forelocks of the prophet sallAllahu 'alaihi wasallam are described as the dark, 27th night of ramadan]. and the parting [maang] is described as being so straight, it is like the sirat e mustaqim and a hundred thousand blessings have been sent upon this straightness. --- i am utterly amazed at these kinds of comparisons and similes. it is beyond words how finely he describes the messenger sallAllahu 'alaihi wasallam.