The Prophet (ﷺ) said: If anyone surrounds a land with a wall, it belongs to him.
Sunan Abi Dawud Book 20, Hadith 150
← Previous Hadith I testify that the Messenger of Allah (ﷺ) decided that the land is the land of Allah, and the servants are the servants of Allah. If anyone brings barren land into cultivation, he has more right to it.

This tradition has been transmitted to us from the Prophet (ﷺ) by those who transmitted the traditions about prayer from him.

Sunan Abi Dawud Book 20, Hadith 149 Next Hadith → Hisham said “The unjust vein means that a man implants a tree in the land of another man so that they may be entitled to it. Malik said “The unjust vein means that a man takes (a thing) digs a pit and implants a tree without (his) right.

Sunan Abi Dawud Book 20, Hadith 151