'Undertaking' in the Bible

And God gave him no heritage in it, not even enough to put his foot on: but he gave him an undertaking that he would give it to him and to his children after him, though he had no child at that time.

But when the time was near for putting into effect the undertaking which God had given to Abraham, the people were increasing in Egypt,

And we are giving you the good news of the undertaking made to the fathers,

And having made Jason and the others give an undertaking to keep the peace, they let them go.