أَلَمْ نَشْرَحْ لَكَ صَدْرَكَ
Have We not expanded your breast for you? (الشرح: 1)
Alam nashraḥ is another case of an acknowledgment-seeking question. The interrogative hamza precedes lam, which places nashraḥ in the jussive; the communicative aim is not to deny the favor but to make the addressee recognize it. The placement of laka also focuses the benefit on the addressed person.
The pattern resembles a-lam yajidka in al-Ḍuḥā: a negative-form question functions as positive reminder. However, “alam always means rhetorical acknowledgment” is too mechanical; the function depends on speaker, audience and context.