Check out Judges 1.1-2:
After the death of Joshua, the people of Israel inquired of the LORD, “Who shall go up first for us against the Canaanites, to fight against them?” The LORD said, “Judah shall go up; behold, I have given the land into his hand.”
It is not by random chance that the the LORD answers “I have given the land into his hand”, and not “I shall give”. The event of Judah actually seizing the land lay in the future, it was not a past event.
The aspect of the verbal form used in this verse is what is in Greek called ‘aorist’, but is in Hebrew more often simply called completed action, or perfective aspect.
The classic advanced biblical Hebrew grammar Gesenius-Kautzsch-Cowley (the latest addition being 1910!) puts it as follows: “The perfect serves to express actions, events, or states, which the speaker wishes to represent from the point of view of completion, whether they belong to a determinate past time, or extend into the present, or while still future, are pictured as in their completed state.”
Another example is Isaiah 9:2: “The people who walked in darkness have seen a great light; those who dwelt in a land of deep darkness, on them has light shone.” The verb ‘seen’ and ‘shone’ are here used in this sense of ‘prophetic perfect’.
God is in control. He is the Lord of all and his plans cannot be frustrated.