Tafsir of Qaf 50:9-11

{Blessed water} Abundant in benefits.

{And the grain of the harvest} The grain of the crops that are meant to be harvested. This refers to what is used for sustenance, such as wheat, barley, and others.

{Lofty} Tall, reaching toward the sky. In the recitation of the Messenger of Allah (ﷺ), it is read as bāṣiqāt (with a ṣād instead of a sīn), due to the proximity of the qāf.

{Layered} Stacked one upon another. This refers either to the abundance and accumulation of the spathes (fruit stalks), or the abundance of the fruit contained within them.

{As provision} This is either a state (ḥāl) derived from "We caused it to grow as provision," because the act of causing growth carries the meaning of providing; or it is a reason (mafʿūl lahu), meaning: "We caused it to grow in order to provide for them."

{Thus is the resurrection} Just as this dead land was brought to life, so too shall you be brought out alive after your death. The kāf (in ka-dhālik) is in the nominative position as the subject (mubtadaʾ).

{The people of Noah denied before them, as did the companions of the Well, Thamud, ʿAd, Pharaoh, the brothers of Lot, the companions of the Thicket, and the people of Tubbaʿ. All of them denied the messengers, so My threat was justly fulfilled.}