The lyrics to the song "Layta lil-Barraqi 'aynan" (If only al-Barraq could see) are extracted from the poem that Layla Bint Lukayz utters from captivity in the epic.  The song was composed by Muhammad al-Qasabgi (1892-1966), having been commissioned by Bahiga Hafez for the film Layla, Daughter of the Desert (1937).  Hayat Muhammad and Ibrahim Hammuda sang the song in the film, but the song was also performed by Asmahan (1917-1944).  

The lyrics in transliteration:

Layta lil-Barraqi 'aynan fa-tara/ma ulaqi min bala'in wa-'ana

'Udhdhibat ukhtukumu ya waylakumu/ bi-'idhabi n-nukri subhan wa-masa

Ghallaluni qayyaduni darabu/gismi n-nahila minni bi-l-'asa

Qayyiduni qhalliluni wa-f'alu/kulla ma shi'tum gami'an min bala

Fa-ana karihatun baghyakumu/wa-yaqin[u] al-mawt[i] shay'un yurtaga

ليتَ للبَرّاقِ عيناً فتَرَى             ما أُلاقي من بَلاءٍ وعَنا

            عُذِّبت اختُكُمُ يا وَيْلَكُم     بِعَذابِ النُكْرِ صُبْحاً ومَسَا

            غَلًّلوني قَيَّدوني ضَرَبوا  جسمي الناحل مِنّي بالعَصا

            قَيِّدوني غلِّلوني وافْعَلوا  كلَّ ما شِئتُم جميعاً من بَلا

            فأنا كارِهةٌ بَغْيَكُمُ           ويَقِينُ المَوْتِ شَيْئٌ يُرْتَجَى