G5063–τεσσαρακονταετής–tessarakontaetēs

`And when forty years were fulfilled to him, it came upon his heart to look after his brethren, the sons of Israel;

τεσσερακονταετὴς tesserakontaetēs “of forty years”

and about a period of forty years He did suffer their manners in the wilderness,

τεσσερακονταετῆ tesserakontaetē “forty years”