Al-Qalam
This chapter comforts the Prophet in the face of the polytheists’ accusation that he is mad. It gladdens him through a beauteous promise and reminds him to be grateful for his noble character. It unilaterally forbids him from obeying them or ceding to their cajoling; instead, it commands him to be steadfast in the face of the divine decree.
The overall context of the verses situates them in Mecca. However, it is narrated from Ibn ʿAbbās and Qatādah that the beginning of the chapter—the first sixteen verses, up until We will brand him on the nose ()—was revealed in Mecca, whereas the next seventeen verses—up until did they but know ()—were revealed in Medina. Then, the next fifteen verses—until so that they write (it) down ()—were revealed in Mecca, and the rest of the chapter—the remaining four verses—was revealed in Medina. There is a point here, since seventeen verses—from Surely We will try them () to did they but know ()—better resemble Medinan rather than Meccan verses.
This is the ʿAllāmah's introduction to the sūrah, from the opening of the commentary.