The Spade in Kingdom Come: Deliverance is an item that will come in handy throughout the game, including for completing quests. One of them, Henry (Indřich) can discover upon returning to Skalitz. See the exact search route below. 

Where to Find the Spade in Skalitz

You'll need to find the spade as part of the quest "Homecoming." The item will be useful for burying the bodies of Henry's slain parents. Upon arrival, Henry will find himself amidst the ashes of his once-beloved village and home. The problem is that the location of the spade is not marked on the map, and you'll have to find it yourself without any hints. 

Proceed forward and descend down the hill from where you discovered your dead parents. Ahead, you'll see a distinctive sight - a sprawling green field. Nearby, you'll hear a dog barking - head in its direction until you come across a hanged man in a black robe. 

From the corpse, turn left and enter the gate into the yard where the peasant is fending off the dog with a spade. You're looking for a house with a high triangular surviving roof. 

In reality, the peasant fending off the dog is shamelessly robbing the corpses. You can punish him for this or resolve the matter peacefully. In any case, the man will flee in fear, leaving his spade behind, or you'll have to fight him bare-handed. 

Pick up the spade to complete this part of the quest and continue the story.