…help from your Lord were to come, they would surely say, “Indeed, we were with you.”
And His words:
“If We so willed, We could certainly take away what We have revealed to you,”
and His words:
“If We defer the punishment from them for a limited term, they will surely say, ‘What is holding it back?’ ”
For this reason the grammarians—such as al-Mubarrad and al-Zajjāj—have said:
“This is the lām of emphatic affirmation that has been prefixed to the conditional particle mā, just as it can be prefixed to an. Its purport is: ‘Whatever Scripture and wisdom I give you, then when a messenger comes to you confirming what you possess, you must believe in him.’ The lām in la-tuʾminunna bihi (‘you shall surely believe in him’) is therefore the apodosis of the condition.”
Al-Farrāʾ likewise said:
“Those who vocalize the lām with fatḥa regard it as an extra lām, akin to the lām that introduces an oath. When it precedes a conditional clause, the ensuing apodosis is treated like a verb whose answering particle functions just as the response to an oath. The meaning is: ‘Whatever Scripture I bring you, then when a messenger comes to you confirming what you possess, you must believe in him.’ The clause la-tuʾminunna bihi is the apodosis. By saying that ‘the apodosis of the condition’ is meant here, they intend that the response to the oath also contains the response to the condition; in meaning it serves as the answer to both.”
The point is that the theoretical and practical wisdom possessed by any nation—if it does not originate with people who believe in Allah and the Last Day and who perform righteous deeds—wins neither Allah’s praise nor His commendation. The philosophers—Aristotle and his followers—were polytheists who worshiped idols and built temples for the heavenly bodies; their wisdom is not the type that Allah praised, nor are its adherents among those He commended. Any Sabian philosopher who was likewise a polytheist belongs to the same category.
The Sabians and the soundest judgment concerning them:
As for the monotheist Sabians (al-Ṣābiʾūn al-ḥunafāʾ), they are to the Sabians what those who faithfully follow the Torah or the Gospel are within their own communities.