Out of laziness, he says to the black donkey “bless me lord.”

This proverb is used when there is an extreamely lazy person. Such a person is so lazy that they don’t even raise their head to see who is standing before them. Thus they confuse a black donkey with a priest who is usually dressed in black. The lazy man addreesses the black donkey as if it is a priest saying, “bless me dear father.