'Covenant' in the Bible

I said, "Please, LORD, God of Heaven, the great and fearsome God who keeps the covenant, showing gracious love to those who love you and keep your commands,

You found him faithful in your sight; you made a covenant with him and you gave the land of the Canaanites, the Hittites, the Amorites, the Perizzites, the Jebusites, and the Girgashites to his descendants. And you have kept your word, because you are righteous.

"Now therefore, our God, the great, mighty, and awesome God, who keeps the covenant and gracious love, don't let all of the difficulties seem trifling to you, all of hardships that have come upon us, upon our kings, upon our leaders, upon our priests, upon our prophets, upon our ancestors, and upon all of your people from the time of the kings of Assyria until this day.

Remember them, my God, because they have defiled the priesthood and the covenant of the priesthood and the descendants of Levi.