Arabic

ˁalā - upon, over; notwithstanding; on account of; in the time of; according to, in conformity to; on the condition of (Lane 2144)

There is also an abbreviated form ˁal attested in poetic texts before the article (Wright 1974 I 281).

PS
*ˁalay - on, over (Arakelova 2001:25)
Throughout EthS this preposition exists only in combination with the element lV. In several languages adverbs of the *lVˁl- type are also attested: see Syr. ləˁal ‘upward, above’, Min. l-ˁl, ‘upward (vers le haut)’ (LM 31), Mnd. lilai ‘upwards’. For the derivation from the PS root *ˁlw/*ˁly ‘to go up’ see Lipiński 1997:466, AED 109, Tropper 2000:766.