Yesīr is interpreted in three ways:
1. Yesīr means "easy"; as in the following verses:
Do you not know that Allah knows what is in the heaven and earth? Indeed, all of this is in a Book. Indeed, that, for Allah, is yesīr {that is, the calamities that will befall are written in the Preserved Tablet (Lawḥ al-Maḥfūẓ); (therefore, knowing them is easy for Allah)}. (al-Ḥajj 22:70)
And no aged person is granted a long life nor is his lifespan lessened but that it is in a Book. Indeed, that, for Allah, is yesīr {that is, it is easy [hīn] for Him. And it is not difficult for Him}. (Fāṭir 35:11)
2. Yesīr is used in the sense of "swift / quick"; as in the following verse:
This is a yesīr measure {that is, a swift/quick measure in which there is no hindrance!}. (Yūsuf 12:65)
3. Yesīr is used in the sense of "hidden / secret"; as in the following verse:
Then We withdraw it yesīrly {that is, secretly} to Ourselves {(that is, We take it back)}. (al-Furqān 25:46)