ייִדישער מחשבֿה אויף תהילים 89:9

The name Jah likewise implies eternal existence. Shadday, however, is derived from day, “enough”; comp. “for the stuff they had was sufficient” (dayyam, Exod. 36:7) the shin is equal to asher, “which,” as in she-kebar, “which already” (Eccles. 2:16). The name Shadday, therefore, signifies “he who is sufficient”; that is to say, He does not require any other being for effecting the existence of what He created, or its conservation: His existence is sufficient for that. In a similar manner the name ḥasin implies “strength”; comp. “he was strong (ḥason) as the oaks” (Amos 2:9). The same is the case with “rock,” which is a homonym, as we have explained (chap. xvi.).